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Background: Deficits in cognitive control are implicated in numerous neuropsychiatric disorders. However, relevant pharmacological treatments are limited, likely due to weak translational validity of applicable preclinical models used. Neural indices derived from electroencephalography may prove useful in comparing and translating the effects of cognition-enhancing drugs between species. In the current study, we aimed to extend our previous cross-species results by examining if methylphenidate (MPH) modulates behavioral and neural indices of cognitive control in independent cohorts of humans and rats., Methods: We measured continuous electroencephalography data from healthy adults (n = 25; 14 female) and Long Evans rats (n = 22; 8 female) and compared both stimulus- and response-locked event-related potentials and spectral power measures across species, and their MPH-related moderation following treatment with vehicle (placebo) or 1 of 2 doses of MPH., Results: Across both species, linear mixed effects modeling confirmed the expected Flanker interference effect on behavior (eg, accuracy) and response-related event-related potentials. Unexpectedly, in contrast to past work, we did not observe any task-related effects on the spectral power of rodents. Moreover, MPH generally did not modulate cognitive control of either species, although some species-specific patterns offer insight for future research., Conclusions: Collectively, these findings in independent human and rodent subjects replicate some of our previously reported behavioral and neurophysiological patterns partly consistent with the notion that similar neural mechanisms may regulate cognitive control in both species. Nonetheless, these results showcase an approach to accelerate translation using a coordinated between-species platform to evaluate pro-cognitive treatments., (© The Author(s) 2024. Published by Oxford University Press on behalf of CINP.)

Background: Methylphenidate is a routinely prescribed treatment for attention-deficit/hyperactivity disorder with misuse potential owing to its perceived performance-enhancing and euphoric properties. Although clinically effective, there is limited understanding of how methylphenidate affects safety-sensitive tasks such as driving when used by healthy individuals., Aim: Explore the acute effects of 10 mg methylphenidate on driving performance and gaze behaviour., Methods: Twenty-five fully licensed, healthy adults (mean age = 33.5 ± 7.8 years, 64% male) took part in two 40-min simulated highway drives with simultaneous eye movements monitored using a proprietary automotive-grade driver monitoring system (Seeing Machines). Driving performance was assessed using the standard deviation of lateral position, standard deviation of speed and steering variability. Visual scanning efficiency was determined using ocular metrics, such as fixation duration and rate, gaze transition entropy, and stationary gaze entropy, were assessed to determine visual scanning efficiency., Results: Methylphenidate significantly improved driving performance by reducing lane weaving and speed variation, particularly in the latter half of the drive. Although a significant reduction in fixation duration was observed, all other ocular metrics remained unchanged., Conclusions: Methylphenidate mitigates performance decrements typically associated with prolonged and monotonous driving. The absence of pronounced oculomotor effects suggests that a single 10 mg dose of methylphenidate has no deleterious impact on visual scanning behaviour during driving tasks with low-to-moderate cognitive demand. Future research should investigate the effects of methylphenidate under various dosing and driving conditions to better understand its impact., Trial Registration: ACTRN12620000499987., Competing Interests: Declaration of conflicting interestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: ACH is supported by a Rebecca L Cooper Al and Val Rosenstrauss Fellowship (GNT: F2021894) and held an NHMRC Early Career Fellowship (GNT: 1119960). LAD received a R.D Wright Career Development Fellowship with no conflicts of interest. BA, SR, and TRA declare no conflicts of interest. BS is employed by Seeing Machines without conflicts of interest related to this publication or any financial support that could affect its outcome.

This research aimed to analyze the therapeutic effect of the pestle needle combined with electroencephalogram (EEG) biofeedback and methylphenidate in the treatment of attention-deficit/hyperactivity disorder (ADHD) in children. Seventy-eight children with ADHD were selected and randomized into a control group and an observation group ( n = 39 each). The control group received EEG biofeedback and methylphenidate treatment, whereas the observation group received pestle needle therapy on this basis. Both groups received continuous treatment for 3 mo. The clinical efficacy, scores of Conners Parents Symptom Questionnaire (PSQ), Integrated Visual and Auditory Continuous Performance Test (IVA-CPT), and Pittsburgh Sleep Quality Index (PSQI), EEG θ/β changes in values, serum indicators such as adrenocorticotropic hormone (ACTH) and cortisol (CORT), and incidence of adverse reactions were compared in the two groups. The total effective rate of the observation group was 92.31% (36/39), which was higher than the control group's 69.23% (27/39) ( P < 0.05). After treatment, reduced PSQ scores, PSQI scores, EEG θ/β values, and ACTH levels and elevated IVA-CPT and CORT levels were observed in both groups; the observation group had the best improvement effect after treatment ( P < 0.05). Pestle needle combined with EEG biofeedback and methylphenidate in the treatment of ADHD children can elevate the IVA-CPT score, improve EEG waves and sleep quality, regulate serum indicators such as ACTH and CORT, reduce behavioral problem scores, and have high efficacy and safety. NEW & NOTEWORTHY The pestle needle combined with EEG biofeedback and methylphenidate in ADHD children can elevate the IVA-CPT score. The pestle needle combined with EEG biofeedback and methylphenidate in ADHD children can improve EEG waves. The pestle needle combined with EEG biofeedback and methylphenidate in ADHD children can improve sleep quality. The pestle needle combined with EEG biofeedback and methylphenidate in ADHD children can regulate serum indicators.

This study explores the under-researched domain of long-term stimulant treatment in children and adolescents diagnosed with attention deficit hyperactivity disorder (ADHD). The necessity for extended treatment duration, often accompanied by safety concerns and side effects leading to treatment discontinuation, underscores the significance of this investigation. Concurrently, comparative studies have revealed adverse impacts on vulnerable regions within the hippocampal formation, accompanied by behavioral perturbations. We employed computerized tests and virtual reality to assess spatial memory, pattern separation, and object recognition memory in a cohort of children diagnosed with ADHD receiving stimulant treatment. We compared their performance to a group of neurotypical peers. Our findings indicate that the ADHD group exhibited a lower performance in spatial memory, pattern separation, and object recognition memory than ND group. Intriguingly, a positive relationship emerged between the duration of stimulant treatment and performance in these variables. Notably, this improvement was not immediate to MPH treatment but becomes significant after 24 months of treatment. In contrast to previous comparative investigations, our study did not reveal a detrimental impact on spatial navigation, object recognition memory, or pattern separation, despite the known interplay of these cognitive processes with the hippocampal formation. These results shed new light on the nuanced effects of stimulant treatment in ADHD, underscoring the need for a more comprehensive understanding of long-term treatment outcomes., Competing Interests: Declaration of Competing All authors certify that they have no affiliations with or involvement in any organization or entity with any financial or nonfinancial interest in the subject matter or materials discussed in this manuscript., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Importance: Depression is a common comorbidity of adult attention-deficit/hyperactivity disorder (ADHD), and the combination of methylphenidate and selective serotonin reuptake inhibitors (SSRIs) is a frequently prescribed treatment. However, there is limited clinical evidence on the safety of this medication combination in adults with ADHD., Objective: To evaluate the safety of administering a combination of SSRI and methylphenidate in adults with ADHD and comorbid depression., Design, Setting, and Participants: This cohort study obtained data from a nationwide claims database in South Korea from January 2016 to February 2021. Participants were adults aged 18 years or older with a diagnosis of ADHD and depressive disorder who were prescribed methylphenidate. Comparisons of 4 groups who received prescriptions were conducted: (1) SSRI plus methylphenidate (hereafter, SSRI) group vs methylphenidate-only group and (2) methylphenidate plus fluoxetine (hereafter, fluoxetine) group vs methylphenidate plus escitalopram (hereafter, escitalopram) group (compared to find a preferable treatment option). Data analysis was conducted between July and December 2023., Exposures: New users of the methylphenidate and SSRI combination among adults with both ADHD and depressive disorder., Main Outcomes and Measures: A total of 17 primary and secondary outcomes, including neuropsychiatric and other events, were assessed, with respiratory tract infection used as a control outcome. Groups were matched at a 1:1 ratio using a propensity score to balance confounders. A Cox proportional hazards regression model was used to calculate hazard ratio (HRs) and 95% CIs. Subgroup analysis by sex and sensitivity analyses in varying epidemiologic settings were conducted., Results: The study included 17 234 adults with ADHD (mean [SD] age at study entry, 29.4 [10.8] years; 9079 females [52.7%]). There was no difference in the risk of outcomes between the methylphenidate-only and SSRI groups, except for a lower risk of headache in the SSRI group (HR, 0.50; 95% CI, 0.24-0.99). In sensitivity analyses of fluoxetine vs escitalopram, the risk of hypertension (HR: 1:n matching, 0.26; 95% CI, 0.08-0.67) and hyperlipidemia (HR: 1:n matching, 0.23; 95% CI, 0.04-0.81) was lower in the fluoxetine group than in the escitalopram group., Conclusions and Relevance: Results of this study revealed no significant increase in adverse event risk associated with use of SSRI plus methylphenidate vs methylphenidate alone in adults with ADHD and comorbid depression. Instead, the combination was associated with a lower risk of headache.

Background: Recent epidemiological data has shown a sharp increase in stimulant use among older adults, which is notable as older adults may be especially vulnerable to their cardiovascular effects. Results of recent studies have shown an increase in cardiovascular events among older adults using stimulants; however, little data exists comparing cardiovascular safety of these agents head-to-head. Objective: To determine if the incidence of serious cardiovascular events, including myocardial infarction (MI), stroke/transient ischemic attack (TIA), or arrhythmia, are different in patients taking amphetamine/dextroamphetamine compared with patients taking methylphenidate. Methods: Retrospective chart review of veterans 50 years and older at the Veterans Affairs North Texas Health Care System (VANTHCS) who were first prescribed a stimulant between 2015 and 2021. The primary outcome was the difference in composite cardiovascular events between amphetamine/dextroamphetamine and methylphenidate. Secondary outcomes were the composite cardiovascular endpoints compared individually (MI, stroke/TIA, or arrhythmia). Hazard ratios were calculated based off of a time-to-event analysis displayed using a Kaplan-Meier curve for primary and secondary outcomes. Results: 466 veterans were screened for inclusion, 30 were excluded, and 436 were included. There was no difference found in composite cardiovascular events between the 241 veterans in the amphetamine/dextroamphetamine group and the 195 veterans in the methylphenidate group with 12 (5%) vs 8 (4.1%) events respectively ( P = .6635). There was also no difference in time-to-event analysis ( P = .4966). Conclusion: In elderly veterans, there was no difference found in incidence of major cardiovascular events with the use of amphetamine/dextroamphetamine compared with methylphenidate., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objectives: Stimulants, such as methylphenidate (MPH) and amphetamines, represent the first-line pharmacological option for attention-deficit/hyperactivity disorder (ADHD). Randomized controlled trials (RCTs) have demonstrated beneficial effects at a group level but could not identify characteristics consistently associated with varying individual response. Thus, more individualized approaches are needed. Experimental studies have suggested that the neurobiological response to a single dose is indicative of longer term response. It is unclear whether this also applies to clinical measures. Methods: We carried out a systematic review of RCTs testing the association between the clinical response to a single dose of stimulants and longer term improvement. Potentially suitable single-dose RCTs were identified from the MED-ADHD data set, the European ADHD Guidelines Group RCT Data set (https://med-adhd.org/), as updated on February 1, 2024. Quality assessment was carried out using the Cochrane Risk of Bias (RoB) 2.0 tool. Results: A total of 63 single-dose RCTs (94% testing MPH, 85% in children) were identified. Among these, only a secondary analysis of an RCT tested the association between acute and longer term clinical response. This showed that the clinical improvement after a single dose of MPH was significantly associated with symptom improvement after a 4-week MPH treatment in 46 children (89% males) with ADHD. The risk of bias was rated as moderate. A further RCT used near-infrared spectroscopy, thus did not meet the inclusion criteria, and reported an association between brain changes under a single-dose and longer term clinical response in 22 children (82% males) with ADHD. The remaining RCTs only reported single-dose effects on neuropsychological, neuroimaging, or neurophysiological measures. Conclusion: This systematic review highlighted an important gap in the current knowledge. Investigating how acute and long-term response may be related can foster our understanding of stimulant mechanism of action and help develop stratification approaches for more tailored treatment strategies. Future studies need to investigate potential age- and sex-related differences.

Competing Interests: The authors have no conflicts of interest to declare.

There is little evidence for psychopharmacotherapy in pica. A few studies reported some benefit from the use of SSRIs, atypical antipsychotics and methylphenidate. That said, evidence to deploy these agents remains, at large, flimsy. Here, despite scarcity, we review available literature and draw some generalities that can inform decision-making on clinical grounds., (Copyright © 1964–2024 by MedWorks Media Inc, Los Angeles, CA All rights reserved. Printed in the United States.)

The co-occurrence Oppositional Defiant Disorder (ODD) in children and adolescents with Attention Deficit Hyperactivity Disorder (ADHD) has been associated to difficulties in regulating adverse states, elevated functional impairment, deficits in Executive Functions and high risk for psychopathology. Recent studies have shown that ODD is a negative predictor of a positive response to methylphenidate (MPH) treatment for ADHD symptoms in children and adolescents and that patients with a diagnosis of comorbid ADHD and ODD are less likely to respond favorably to pharmacological treatment with MPH. We conducted a naturalistic study to understand the clinical characteristics of drug-naïve children and adolescents with ADHD that influence the response to MPH by measuring the effect on attention. Specifically, we investigated whether a single dose of MPH differently affects the performance of 53 children and adolescents with ADHD with or without ODD comorbidity. In addition, participant characteristics such as symptom severity, functional impairment, and associated behavioral and emotional symptoms at baseline were examined to better understand what aspects affect the response to MPH. We found that a single dose of MPH improved the attention of children and adolescents with ADHD without ODD more than those with comorbid ADHD and ODD, resulting in reduced reaction times. Our findings indicated that children and adolescents with comorbid ADHD and ODD and those with ADHD alone did not exhibit differences in measures of attention prior to taking MPH, nor in demographic variables (age, intelligence quotient, gender), clinical characteristics related to symptom severity, and adaptive behaviors. However, we observed differences between the two groups in certain behavioral aspects, including the Dysregulation Profile and disruptive behaviors. Assessing symptoms in combination with the presence of ADHD can be beneficial in determining which individuals would derive the greatest benefits from treatment., Competing Interests: The authors have no financial or proprietary interests in any material discussed in this article., (Copyright: © 2024 D’Aiello et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Objective: To compare safety and efficacy of centanafadine versus methylphenidate hydrochloride extended release (ER; Concerta) in adults with ADHD., Methods: Without head-to-head trials, anchored matching-adjusted indirect comparisons (MAIC) of adverse event rates reported across trials and mean change from baseline in Adult ADHD Investigator Symptom Rating Scale (AISRS) score between centanafadine and methylphenidate hydrochloride ER were conducted. Pooled patient-level data from two centanafadine trials (NCT03605680/NCT03605836) and aggregate data from one published methylphenidate hydrochloride ER trial (NCT00937040) were used. Characteristics of individual patients from the centanafadine trials were matched to aggregate baseline characteristics from the methylphenidate hydrochloride ER trial using propensity score weighting. A sensitivity analysis assessed the robustness of the results to the capping of extreme weights (i.e. >99 th percentile)., Results: Compared with methylphenidate hydrochloride ER, centanafadine was associated with significantly lower risk of dry mouth (risk difference [RD] in percentage points: -11.95), initial insomnia (-11.10), decreased appetite (-8.05), anxiety (-5.39), palpitations (-5.25), and feeling jittery (-4.73) though a significantly smaller reduction in AISRS score (4.16-point). In the sensitivity analysis, the safety results were consistent with the primary analysis but there was no significant difference in efficacy between centanafadine and methylphenidate hydrochloride ER., Conclusion: In this MAIC, centanafadine had better safety and possibly lower efficacy than methylphenidate hydrochloride ER. While safety results were robust across analyses, there was no efficacy difference between centanafadine and methylphenidate hydrochloride ER in the sensitivity analysis. Considering its favorable safety profile, centanafadine may be preferred among patients for whom treatment-related adverse events are a concern.

A single dose of psilocybin, a psychedelic that acutely causes distortions of space-time perception and ego dissolution, produces rapid and persistent therapeutic effects in human clinical trials 1-4 . In animal models, psilocybin induces neuroplasticity in cortex and hippocampus 5-8 . It remains unclear how human brain network changes relate to subjective and lasting effects of psychedelics. Here we tracked individual-specific brain changes with longitudinal precision functional mapping (roughly 18 magnetic resonance imaging visits per participant). Healthy adults were tracked before, during and for 3 weeks after high-dose psilocybin (25 mg) and methylphenidate (40 mg), and brought back for an additional psilocybin dose 6-12 months later. Psilocybin massively disrupted functional connectivity (FC) in cortex and subcortex, acutely causing more than threefold greater change than methylphenidate. These FC changes were driven by brain desynchronization across spatial scales (areal, global), which dissolved network distinctions by reducing correlations within and anticorrelations between networks. Psilocybin-driven FC changes were strongest in the default mode network, which is connected to the anterior hippocampus and is thought to create our sense of space, time and self. Individual differences in FC changes were strongly linked to the subjective psychedelic experience. Performing a perceptual task reduced psilocybin-driven FC changes. Psilocybin caused persistent decrease in FC between the anterior hippocampus and default mode network, lasting for weeks. Persistent reduction of hippocampal-default mode network connectivity may represent a neuroanatomical and mechanistic correlate of the proplasticity and therapeutic effects of psychedelics., (© 2024. The Author(s).)

We conducted a 12-week randomized double-blind placebo-controlled clinical trial to investigate the potential impact of Bifidobacterium bifidum ( Bf-688 ) supplementation on attention-deficit/hyperactivity disorder (ADHD). Children with ADHD who were already receiving a stable dose of methylphenidate (MPH) treatment were enrolled and were randomly assigned to two groups: one receiving add-on Bf-688 (daily bacterial count of 5 × 10 9 CFUs) ( n = 51) and the other receiving a placebo ( n = 51). All participants underwent assessments using Conners' Continuous Performance Test (CPT) and Conners' Continuous Auditory Test of Attention (CATA). Additionally, fecal samples were collected at the beginning of the trial (week 0) and at the endpoint (week 12). Remarkably, the group receiving Bf-688 supplementation, but not the placebo group, exhibited significant improvements in omission errors in CPT as well as Hit reaction time in both CPT and CATA. Gut microbiome analysis revealed a significant increase in the Firmicutes to Bacteroidetes ratio ( F/B ratio) only in the Bf-688 group. Furthermore, we identified significant negative correlations between N-Glycan biosynthesis and Hit reaction time in both CPT and CATA. Our results demonstrate that the probiotic Bf-688 supplement can enhance neuropsychological performance in children with ADHD, possibly by altering the composition of the gut microbiota, ultimately leading to reduced N-Glycan biosynthesis.

Purpose: To compare effects and side effects of 6 weeks of individually dose-titrated methylphenidate or placebo on fatigue in palliative care patients with advanced cancer., Methods: This is a randomized, double-blind, placebo-controlled, multicenter trial. Eligible patients had advanced incurable cancer and fatigue >3/10. Principal exclusions were hypertension; psychiatric, cardiovascular, cerebrovascular, renal, liver, or blood disorders; substance dependency; and epilepsy. Patients were randomly assigned 1:1 methylphenidate or placebo starting at 5 mg twice daily. Dose of methylphenidate/placebo was titrated once per week, over 6 weeks, up to a maximum of 20 mg three times daily. Trial ended at 10 weeks. Primary outcome was the difference in Functional Assessment of Chronic Illness Therapy Fatigue (FACIT-F) scores between groups at 6 ± 2 weeks. Secondary outcomes included adverse effects, quality of life, and mood., Results: One hundred sixty-two patients (73 men; mean, 65.8; standard deviation [SD], 10.3 years) were randomly assigned, and three were excluded from analysis. Seventy-seven were allocated placebo (baseline FACIT-F = 22 [SD, 10]); 82 were allocated methylphenidate (FACIT-F = 20 [SD, 9]). After 6 ± 2 weeks, FACIT-F scores were 1.97 points (95% CI, -0.95 to 4.90; P = .186) higher (better) on methylphenidate than placebo. Across 10 weeks of the study, FACIT-F was nominally higher in the methylphenidate group versus placebo (Diff, 2.20 [95% CI, 0.39 to 4.01]), but this did not reach the minimally clinically important difference (5-points). At 6 weeks, there were no differences between groups in quality-of-life or symptom domains except for depression scores (nominally reduced in the methylphenidate group: Diff, -1.35 [95% CI, -2.41 to -0.30]). There were no differences in mortality or serious adverse events., Conclusion: After 6 ± 2 weeks of treatment, methylphenidate was not superior to placebo for treating fatigue in advanced cancer. Methylphenidate was safe and well-tolerated.

Attention-Deficit/Hyperactivity Disorder (ADHD) is associated with executive function deficits that are improved with medications. However, meta-analyses of stimulant effects on cognition have mostly tested single-dose effects, and there is no meta-analysis of non-stimulant effects. This systematic review and meta-analysis tested the clinically more relevant longer-term effects of Methylphenidate (20 studies; minimum 1 week) and Atomoxetine (8 studies; minimum 3 weeks) on reaction time, attention, inhibition, and working memory, searching papers on PubMed, Embase, Ovid MEDLINE, and PsycINFO. The meta-analysis of 18 studies in 1667 subjects showed that methylphenidate was superior to placebo in all cognitive domains with small to medium effect sizes (Hedges g of 0.34-0.59). The meta-analysis of atomoxetine included 7 studies in 829 subjects and showed no effects in working memory, but superior effects in the other domains with medium to large effect sizes (Hedge's g of 0.36-0.64). Meta-regression analysis showed no drug differences on cognitive effects. The meta-analyses show for the first time that chronic Methylphenidate and Atomoxetine have comparable effects of improving executive functions in people with ADHD., Competing Interests: Declaration of competing interests KR has received funding from TAKEDA for another project. The other authors have no conflict of interest., (Copyright © 2024. Published by Elsevier Ltd.)

Background: The Default Mode Network (DMN) is a central neural network, with recent evidence indicating that it is composed of functionally distinct sub-networks. Methylphenidate (MPH) administration has been shown before to modulate impulsive behavior, though it is not yet clear whether these effects relate to MPH-induced changes in DMN connectivity. To address this gap, we assessed the impact of MPH administration on functional connectivity patterns within and between distinct DMN sub-networks and tested putative relations to variability in sub-scales of impulsivity., Methods: Fifty-five right-handed healthy adults underwent two resting-state functional MRI (rs-fMRI) scans, following acute administration of either MPH (20 mg) or placebo, via a randomized double-blind placebo-controlled design. Graph modularity analysis was implemented to fractionate the DMN into distinct sub-networks based on the impact of MPH (vs. placebo) on DMN connectivity patterns with other neural networks., Results: MPH administration led to an overall decreased DMN connectivity, particularly with the auditory, cinguloopercular, and somatomotor networks, and increased connectivity with the parietomedial network. Graph analysis revealed that the DMN could be fractionated into two distinct sub-networks, with one exhibiting MPH-induced increased connectivity and the other decreased connectivity. Decreased connectivity of the DMN sub-network with the cinguloopercular network following MPH administration was associated with elevated impulsivity and non-planning impulsiveness., Conclusion: Current findings highlight the intricate effects of MPH administration on DMN rs-fMRI connectivity, uncovering its opposing impact on distinct DMN sub-divisions. MPH-induced dynamics in DMN connectivity patterns with other neural networks may account for some of the effects of MPH administration on impulsive behavior., (© 2024. The Author(s).)

Purpose: To determine the structure and properties of corneal endothelial cells in children and adolescents with ADHD who received methylphenidate treatment at least six months., Method: The prospective, observational study included 33 eyes of 33 patients diagnosed with ADHD who received methylphenidate treatment for at least six months, 33 eyes of 33 patients newly diagnosed with ADHD who did not start medication treatment, and 33 eyes of 33 healthy individuals. Average cell density, coefficient of variation, maximum cell area, normal cell area, minimum cell area, average cell area, and hexagonality ratio values were evaluated by non-contact specular microscopy. The parameters recorded in all three groups were compared., Results: The average age of children in the ADHD + MPH, ADHD, and control groups is 9 ± 1.7, 8.9 ± 2.3, and 8.9 ± 1.8 years, respectively. ( p  > 0.05) The average MPH treatment dose is 0.94 ± 0.19 mg/kg, the average daily MPH intake is 34.12 ± 14.04 mg, and the average duration of use of MPH is 24.03 ± 12.46 months. Central corneal thickness (CCT) was measured as an average of 540.45 ± 31.23 in the ADHD + MPH group, 540.61 ± 29.69 in the ADHD group, and 546.58 ± 27.72 in the control group. ( p  = 0.499) The average coefficient of variation (CV) values were measured as 25.48 ± 4.22 in the ADHD + MPH group, 26.12 ± 3.48 in the ADHD group, and 26.12 ± 3.64 in the control group. ( p  = 0.491) The average hexagonality ratio (%) (HEX) values were measured as 69.45 ± 8.41 in the ADHD + MPH group, 68.21 ± 6.82 in the ADHD group, and 68.91 ± 7.97 in the control group. ( p  = 0.892) No statistically significant difference was observed between all three groups in terms of all parameters., Conclusion: Methylphenidate treatment administered for at least six months with a diagnosis of ADHD did not have a toxic effect on the corneal endothelium.

More knowledge is needed about long-term ADHD medication and symptom, daily functioning, comorbidity, and tolerability outcomes. This "Long-term Medication for ADHD (LMA) trial" was a prospective observational 2-year trial in children and adolescents aged 6-18 years (extension of 1-year trial). Participants met criteria for DSM-5 ADHD (inattentive or combined), with complex comorbidities; autism spectrum disorder (31%), autistic traits (24%), oppositional symptoms (59%), anxiety (32%), dyslexia/language disorder (16%), borderline intellectual functioning (17%). Medication was individually tailored and followed-up at clinical visits (1, 2, 3, 6, 12, 18, 24 months). Primary outcome: Clinical Global Impression-Severity and Improvement scales (CGI-S, CGI-I). Secondary outcomes: Investigator-rated ADHD-Rating Scale, Weiss Functional Impairment Rating Scale-Parent report (WFIRS-P; Family, School Learning and Behavior, Life Skills, Self-Concept, Social Activities, and Risky Activities domains), comorbidity symptoms and adverse events (AEs). One hundred twenty-eight participants were enrolled (1-year trial only n = 27, LMA trial n = 101). Of these 29 (23%) discontinued, mainly due to AEs (n = 7), moving (n = 7), or no longer needing medication (n = 6). Main AEs were poor appetite, low mood, anxiety, irritability, fatigue. Improvements from baseline to 2 years were large in CGI-S (effect size (ES) 2.28), ADHD-RS (ES 2.06), and moderate to large in WFIRS-P (ES total 0.73, learning 0.4, family 0.67). Overall, the trial showed robust and sustained improvements in ADHD symptom severity and daily functioning over a period of 2 years of ADHD medication in children and adolescents with ADHD and complex comorbidities. Most AEs were mild. Comorbidity symptoms were improved after 1 year, particularly oppositional symptoms, depression, and anxiety., (© 2024. The Author(s).)

With more than 30 available stimulant medications, choosing among therapeutic options for attention-deficit/hyperactivity disorder (ADHD) has become increasingly complex and patient specific. All ADHD stimulants owe their action to variants of either amphetamine or methylphenidate, yet formulation and delivery system differences create unique pharmacokinetic and clinical profiles for each medication. A benefit of the diversity within ADHD pharmacotherapy is that it facilitates tailoring treatment to meet patient needs. Historically, there has been a constant among long-acting stimulant options, regardless of formulation, which was morning dosing. The introduction of delayed-release and extended-release methylphenidate (DR/ER-MPH) is the first long-acting stimulant that patients take in the evening, with the clinical effect delayed until awakening in the morning. This paradigm shift has generated questions among clinicians and continued interest in real-world experience and data. This review used available clinical data, real-world evidence, emerging analyses, and clinical experience to evaluate the characteristics of DR/ER-MPH and its clinical utility within the greater context of ADHD medications and to provide clinicians with practical guidance on the use of DR/ER-MPH in children, adolescents, and adults with ADHD.

Objective: DR/ER-MPH (formerly HLD200) is an evening-dosed delayed-release and extended-release methylphenidate approved for the treatment of ADHD in patients ≥6 years. Post hoc analyses of two pivotal Phase 3 trials: HLD200-107 (NCT02493777) and HLD200-108 (NCT02520388) evaluated emotional lability (EL) with DR/ER-MPH treatment., Methods: Differences in Conners Global Index-Parent (CGI-P) EL subscale scores and age- and gender-adjusted T -scores over an open-label titration phase (HLD200-107) and between treatment and placebo groups at endpoint (HLD200-108) were evaluated., Results: In HLD200-107 ( N  = 117) mean CGI-P EL subscale scores improved from 5.3 to 1.3 ( p  < .0001) after 6 weeks; in HLD200-108 significant improvements were observed in the treatment group ( n  = 81) versus placebo ( n  = 80; 3.11 vs. 4.08; p  = .0053). T -scores showed an improvement with DR/ER-MPH treatment in both trials. Few emotional adverse events (AEs) were reported., Conclusion: DR/ER-MPH treatment resulted in statistically significant improvements in EL to the level of non-ADHD peers as contextualized by T -scores., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: VKA: Advisory Board/Consultant—Ironshore, Neos, Rho, Shire; Speakers Bureau—Ironshore Pharmaceuticals Inc., Lundbeck/Takeda. FAL: Consultant, Speaker, and/or Research Support—Cingulate, Corium, Eli Lilly, GSK, Ironshore, Neos, Novartis, Noven, Pfizer, Rhodes, Shionogi, Shire, Sunovion, Supernus, Tris. ACC: Research Support—Acadia, Akili Interactive Labs, Allergan, Arbor Pharmaceuticals, LLC, Axial, Cingulate, Corium, Emalex, Forest Laboratories, Ironshore, KemPharm, Inc., Lumos, Neos Therapeutics, Neurocentria, Otsuka America Pharmaceutical, Inc., Purdue Pharma, Rhodes Pharmaceuticals, Servier, Shire, Sunovion Pharmaceuticals, Inc., Supernus Pharmaceuticals, Inc., Takeda Pharmaceutical Company Ltd., Tris Pharma, Advisory Board—Adlon, Akili Interactive Labs, Arbor Pharmaceuticals, LLC, Cingulate Therapeutics, Otsuka America Pharmaceutical, Inc., Pfizer, Purdue Pharma, Shire, Sunovion Pharmaceuticals, Inc., Supernus Pharmaceuticals, Inc., Takeda Pharmaceutical Company Ltd., Tris Pharma; Consultant—Arbor Pharmaceuticals, LLC, Aytu, Attentive Therapeutics, Corium, Ironshore, KemPharm, Inc., Lumos, Neos Therapeutics, Neurocentria, ., Purdue Pharma, Sunovion Pharmaceuticals, Inc., Supernus Pharmaceuticals, Inc., Tris Pharma; Speakers Bureau—Ironshore, Takeda Pharmaceutical Company Ltd., Tris Pharma; Writing Support—Arbor Pharmaceuticals, LLC, Ironshore, Neos Therapeutics, Pfizer, Purdue Pharma, Rhodes Pharmaceuticals, Shire, Sunovion Pharmaceuticals, Inc., Takeda Pharmaceutical Company Ltd., Tris Pharma. MDP, CLU, LC, and BI: Employees—Ironshore. FRS: Employee—Ironshore; Advisory Board/Board of Directors—P2D Bioscience.

Background: Symptoms of anxiety and depression are common in patients with terminal illness and multiple challenges exist with timely and effective care in this population. Several centres have reported that one dose of the serotonergic psychedelic psilocybin, combined with therapeutic support, improves these symptoms for up to 6 months in this patient group. Drawing upon related therapeutic mechanisms, 3,4-methylenedioxymethamphetamine (MDMA)-assisted therapy may have the potential to achieve similar, positive mental health outcomes in this group. Preliminary evidence also supports the tolerability of MDMA-assisted therapy for anxiety and depression in advanced-stage cancer., Methods: Up to 32 participants with advanced-stage cancer and associated depression and anxiety will be randomised in a 1:1 ratio into one of two blinded parallel treatment arms. The intervention group will receive 120 mg (+ 60 mg optional supplemental dose) MDMA-assisted therapy. The psychoactive control group will receive 20 mg oral (+ 10 mg optional supplemental dose) methylphenidate-assisted therapy. For each medication-assisted therapy session, participants will undergo two 90-min therapeutic support sessions in the week preceding, and one 90-min support session the day after the experimental session. A battery of measures (mood, anxiety, quality of life, mystical experience, spiritual wellbeing, attitudes towards death, personality traits, holistic health and wellbeing, connectedness, demoralisation, expectations, qualitative data and safety measures) will be assessed at baseline and through to the end of the protocol. Participants will be followed up until either 12 months post-randomisation or death, whichever occurs first., Discussion: This study will examine the effect of MDMA-assisted therapy on symptoms of anxiety and depression in advanced-stage cancer. Potential therapeutic implications include establishing the safety and effectiveness of a novel treatment that may relieve mental suffering in patients with life-threatening illness., Trial Registration: Trial registered on Australian New Zealand Clinical Trials Registry., Registration Number: ACTRN12619001334190p. Date registered: 30/09/2019. URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=378153&showOriginal=true&isReview=true., (© 2024. The Author(s).)

Background and Objectives: Concerns exist regarding the rising use of methylphenidate. A double-blind, placebo-controlled methylphenidate titration (PCT) for children with attention-deficit/hyperactivity disorder (ADHD) has shown potential to improve titration (i.e., detection of placebo responders and larger ADHD symptom improvement) in experimental settings. This study aims to determine if these advantages can be transferred to clinical settings., Method: Children (aged 5-13 years) with an ADHD diagnosis and an indication to start methylphenidate (MPH) treatment were recruited. Participants were randomized to PCT or care as usual (CAU) in a 1:1 ratio followed by a 7-week randomized controlled trial (T1) and 6-month, naturalistic, open-label follow-up (T2). Parents, teachers, and physicians rated ADHD symptoms, ADHD medication use, MPH dosing, and treatment satisfaction using questionnaires., Results: A total of 100 children were enrolled and randomized to PCT (n = 49) or CAU (n = 51). In the PCT group, we found 8.2% placebo responders, 16.3% non-responders, and 65.3% responders to MPH. With PCT compared with CAU, a significantly larger number of children discontinued MPH (T1: 24.5 vs 5.9%, p = 0.009; T2: 41.7 vs 10.4%, p < 0.001) and refrained from using other pharmacological treatment (T1: 20.4 vs 3.9%, p = 0.013; T2: 20.83 vs 6.25%, p = 0.002). At both timepoints, there were no significant differences between the groups in the average dose of MPH, ADHD symptoms, or treatment satisfaction., Conclusions: PCT can be used to improve detection of children who do not benefit from MPH, and may therefore potentially reduce overtreatment of ADHD with MPH., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Methylphenidate (MP) is commonly prescribed to treat attention-deficit hyperactivity disorder (ADHD). MP is also taken for non-medical purposes as a recreational drug or "cognitive enhancer". Combined exposure to MP and selective serotonin reuptake inhibitors such as fluoxetine (FLX) can also occur, such as in the treatment of ADHD with depression comorbidity or when patients taking FLX use MP for non-medical purposes. It is unclear if such exposure could subsequently increase the risk for relapse in former cocaine users. We investigated if an acute challenge with MP, FLX, or the combination of MP + FLX could trigger reinstatement of cocaine seeking behavior in a model for relapse in rats. Juvenile rats self-administered cocaine (600 µg/kg/infusion, 1-2 h/day, 7-8 days) and then underwent extinction and withdrawal during late adolescence-early adulthood. Reinstatement was tested at a low dose of MP (2 mg/kg, I.P., comparable to doses used therapeutically) or a high dose of MP (5 mg/kg, comparable to doses used recreationally or as a cognitive enhancer), with or without FLX (2.5-5 mg/kg, I.P.). An acute challenge with the high dose of MP (5 mg/kg), with or without FLX, reinstated cocaine seeking behavior to levels comparable to those seen after an acute challenge with cocaine (15 mg/kg, I.P.). The low dose of MP (2 mg/kg) with or without FLX did not reinstate cocaine seeking behavior. Our results suggest that acute exposure to a high dose of MP, with or without FLX, may increase the risk for relapse in individuals who used cocaine during the juvenile period., (© 2023. The Author(s), under exclusive licence to American College of Neuropsychopharmacology.)

Case: DL is an 8-year-old Mexican boy with a posterior atrial septal defect and partial anomalous pulmonary venous return of the right lower pulmonary vein with resultant right heart dilation with normal right ventricular systolic and diastolic function and no arrhythmias. Surgical repair was deferred, and DL's condition was being medically managed with furosemide 0.5 mg/kg BID and spironolactone 0.5 mg/kg BID.DL presents for developmental assessment due to poor performance in school following a lifting of COVID-19 pandemic restrictions and return to in-person classes. He has been attending full-time classes for 3 months without improvements in math, reading, and writing skills. Current attentional concerns at school include an inability to complete tasks without getting distracted by minimal stimuli and highly impulsive behavior.At the first assessment, DL was performing below grade expectations (e.g., reading by syllable without text comprehension, demonstrating preoperational addition and subtraction skills, inability to take dictation)-all of which was viewed as negatively impacted by attentional deficits. DL met DSM-5 criteria for ADHD, predominantly inattentive type. He was started on 10-mg immediate-release methylphenidate PO at 8 am with breakfast and a second dose of 10-mg immediate-release methylphenidate PO 4 hours after the first dose.After a month, at the first follow-up consultation, improvement in attention span, impulsivity, and school performance were observed, including reading skills and math proficiency. However, DL's mother raised concerns about circumoral cyanosis and acrocyanosis in the fingers of both hands after playing outside. These signs were not previously observed. During physical examination at the same visit, heart rate, blood pressure, and oximetry were within baseline ranges and his cardiac examination was unchanged. DL's dosage of methylphenidate was lowered to 10-mg immediate-release methylphenidate PO QD in the mornings with breakfast (8 am).DL did not return to clinic for another 2 months, having discontinued the medication after 2 months of treatment given financial limitations. His mother reported that DL's exertional circumoral cyanosis and acrocyanosis resolved while he was off medication. However, she observed an increase in inattentive symptoms and impulsivity and decline in his academic skills. She asked if our team was able continue the treatment despite the drug side effects, since she believed the benefits outweighed the disadvantages.Given these concerns, the team requested an updated cardiology assessment. The Cardiologist recommended discontinuation of methylphenidate and recommended follow-up with cardiothoracic surgery for reassessment of the surgical timeline.Given the limited treatment options in Mexico, what would you do next as the treating developmental-behavioral clinician…?, (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

The rewarding effects of stimulant drugs such as methylphenidate (MP) depend crucially on how fast they raise dopamine in the brain. Yet how the rate of drug-induced dopamine increases impacts brain network communication remains unresolved. We manipulated route of MP administration to generate fast versus slow dopamine increases. We hypothesized that fast versus slow dopamine increases would result in a differential pattern of global brain connectivity (GBC) in association with regional levels of dopamine D1 receptors, which are critical for drug reward. Twenty healthy adults received MP intravenously (0.5 mg/kg; fast dopamine increases) and orally (60 mg; slow dopamine increases) during simultaneous [ 11 C]raclopride PET-fMRI scans (double-blind, placebo-controlled). We tested how GBC was temporally associated with slow and fast dopamine increases on a minute-to-minute basis. Connectivity patterns were strikingly different for slow versus fast dopamine increases, and whole-brain spatial patterns were negatively correlated with one another (rho = -0.54, p spin  < 0.001). GBC showed "fast>slow" associations in dorsal prefrontal cortex, insula, posterior thalamus and brainstem, caudate and precuneus; and "slow>fast" associations in ventral striatum, orbitofrontal cortex, and frontopolar cortex (p FDR  < 0.05). "Fast>slow" GBC patterns showed significant spatial correspondence with D1 receptor availability (estimated via normative maps of [ 11 C]SCH23390 binding; rho = 0.22, p spin  < 0.05). Further, hippocampal GBC to fast dopamine increases was significantly negatively correlated with self-reported 'high' ratings to intravenous MP across individuals (r (19)  = -0.68, p bonferroni  = 0.015). Different routes of MP administration produce divergent patterns of brain connectivity. Fast dopamine increases are uniquely associated with connectivity patterns that have relevance for the subjective experience of drug reward., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Objective: To understand how methylphenidate (MPH) is used in youth with traumatic brain injury (TBI) during inpatient pediatric rehabilitation., Setting: Inpatient pediatric rehabilitation., Participants: In total, 234 children with TBI; 62 of whom received MPH and 172 who did not. Patients were on average 11.6 years of age (range, 2 months to 21 years); 88 of 234 were female; the most common mechanism of injury was motor vehicle collision (49%); median (IQR) acute hospital length of stay (LOS) and inpatient rehabilitation LOS were 16 (10-29) and 23 (14-39), respectively; 51 of 234 were in a disorder of consciousness cognitive state at time of inpatient rehabilitation admission., Design: Multicenter, retrospective medical record review., Main Measures: Patient demographic data, time to inpatient pediatric rehabilitation admission (TTA), cognitive state, MPH dosing (mg/kg/day)., Results: Patients who received MPH were older (P = .011); TTA was significantly longer in patients who received MPH than those who did not (P =.002). The lowest recorded dose range by weight was 0.05 to 0.89 mg/kg/d, representing an 18-fold difference; the weight-based range for the maximum dose was 0.11 to 0.97 mg/kg/d, a 9-fold difference. Patients in lower cognitive states at admission (P = .001) and at discharge (P = .030) were more likely to receive MPH. Five patients had side effects known to be associated with MPH; no serious adverse events were reported., Conclusion: This multicenter study indicates that there is variable use of MPH during acute inpatient rehabilitation for children with TBI. Children who receive MPH tend to be older with lower cognitive states. Dosing practices are likely consistent with underdosing. Clinical indications for MPH use during inpatient pediatric rehabilitation should be better defined. The use of MPH, as well as its combination with other medications and treatments, during inpatient rehabilitation needs to be further explored., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

The rapid serial visual presentation (RSVP) task and continuous performance tasks (CPT) are used to assess attentional impairments in patients with psychiatric and neurological conditions. This study developed a novel touchscreen task for rats based on the structure of a human RSVP task and used pharmacological manipulations to investigate their effects on different performance measures. Normal animals were trained to respond to a target image and withhold responding to distractor images presented within a continuous sequence. In a second version of the task, a false-alarm image was included, so performance could be assessed relative to two types of nontarget distractors. The effects of acute administration of stimulant and nonstimulant treatments for ADHD (amphetamine and atomoxetine) were tested in both tasks. Methylphenidate, ketamine, and nicotine were tested in the first task only. Amphetamine made animals more impulsive and decreased overall accuracy but increased accuracy when the target was presented early in the image sequence. Atomoxetine improved accuracy overall with a specific reduction in false-alarm responses and a shift in the attentional curve reflecting improved accuracy for targets later in the image sequence. However, atomoxetine also slowed responding and increased omissions. Ketamine, nicotine, and methylphenidate had no specific effects at the doses tested. These results suggest that stimulant versus nonstimulant treatments have different effects on attention and impulsive behaviour in this rat version of an RSVP task. These results also suggest that RSVP-like tasks have the potential to be used to study attention in rodents., (© 2024. The Author(s).)

BACKGROUND AND OBJECTIVE: Attention deficit hyperactivity disorder is one of the most common neuropsychiatric conditions in children, and methylphenidate (MPH) is one of the first-line therapies. MPH is available in a variety of extended-release (ER) formulations worldwide, and most formulations are not considered bioequivalent due to differences in pharmacokinetics. It is hypothesized that the current bioequivalence guidelines from the different regulatory bodies may generate inconsistent findings or recommendations when assessing the bioequivalence of ER MPH formulations. This manuscript aims to conduct a comprehensive and narrative critical literature review to analyze pharmacokinetic data pertaining to ER formulations of MPH in order to assess bioequivalence, differences in regulatory guidelines, and additional pharmacokinetic-pharmacodynamic parameters that may help define interchangeability., Methods: A literature search was conducted in EMBASE, Medline, and Cochrane Library with no time limits. Study characteristics, non-compartmental pharmacokinetic parameters, and bioequivalence data were extracted for analysis., Results: Thirty-three studies were identified with primary pharmacokinetic data after the administration of ER MPH, of which 10 were direct comparative studies (i.e., at least 2 formulations tested within a single setting) and 23 were indirect comparisons (i.e., different experimental settings). Two formulations were consistently reported as bioequivalent across the regulatory bodies using criteria from their guidance documents, although inconsistencies have been observed. However, when additional kinetic criteria (discussed in this manuscript) were imposed, only one study met the more stringent definition of bioequivalence. Various clinical factors also had inconsistent effects on the pharmacokinetics and interchangeability of the different formulations, which were associated with a lack of standardization for assessing covariates across the regulatory agencies., Conclusion: Additional pharmacokinetic parameters and consistency in guidelines across the regulatory bodies may improve bioequivalence assessments. Based on our findings, more research is also required to understand whether bioequivalence is an appropriate measure for determining MPH interchangeability. This critical review is suitable for formulation scientists, clinical pharmacologists, and clinicians., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Importance: Stimulants (methylphenidate and amphetamines) are often prescribed at unlicensed doses for adults with attention-deficit/hyperactivity disorder (ADHD). Whether dose escalation beyond US Food and Drug Administration recommendations is associated with positive risk benefits is unclear., Objective: To investigate the impact, based on averages, of stimulant doses on treatment outcomes in adults with ADHD and to determine, based on averages, whether unlicensed doses are associated with positive risk benefits compared with licensed doses., Data Sources: Twelve databases, including published (PubMed, Cochrane Library, Embase, Web of Sciences) and unpublished (ClinicalTrials.gov) literature, up to February 22, 2023, without language restrictions., Study Selection: Two researchers independently screened records to identify double-blinded randomized clinical trials of stimulants against placebo in adults (18 years and older) with ADHD., Data Extraction and Synthesis: Aggregate data were extracted and synthesized in random-effects dose-response meta-analyses and network meta-analyses., Main Outcome Measures: Change in ADHD symptoms and discontinuations due to adverse events., Results: A total of 47 randomized clinical trials (7714 participants; mean age, 35 (SD, 11) years; 4204 male [56%]) were included. For methylphenidate, dose-response curves indicated additional reductions of symptoms with increments in doses, but the gains were progressively smaller and accompanied by continued additional risk of adverse events dropouts. Network meta-analyses showed that unlicensed doses were associated with greater reductions of symptoms compared with licensed doses (standardized mean difference [SMD], -0.23; 95% CI, -0.44 to -0.02; very low certainty of evidence), but the additional gain was small and accompanied by increased risk of adverse event dropouts (odds ratio, 2.02; 95% CI, 1.19-3.43; moderate certainty of evidence). For amphetamines, the dose-response curve approached a plateau and increments in doses did not indicate additional reductions of symptoms, but there were continued increments in the risk of adverse event dropouts. Network meta-analysis did not identify differences between unlicensed and licensed doses for reductions of symptoms (SMD, -0.08; 95% CI, -0.24 to 0.08; very low certainty of evidence)., Conclusions and Relevance: Based on group averages, unlicensed doses of stimulants may not have positive risk benefits compared with licensed doses for adults with ADHD. In general, practitioners should consider unlicensed doses cautiously. Practitioners may trial unlicensed doses if needed and tolerated but should be aware that there may not be large gains in the response to the medication with those further increments in dose. However, the findings are averages and will not generalize to every patient.

Methylphenidate (MP) is extensively prescribed for attention deficit hyperactivity disorder (ADHD). While MP is effective in ameliorating symptoms of ADHD, MP is also used illicitly among healthy subjects without ADHD for cognitive-enhancing purposes. The deleterious consequences associated with long-term MP use as well as its cessation on brain activity remains to be understood. To address this, we administered either water, low dose MP (LD MP), or high dose MP (HD MP) to healthy adolescent Sprague Dawley rats, with five days on the treatment and two days off for thirteen consecutive weeks. Rats were then abstinent from their respective treatments for four weeks. Using positron emission tomography (PET) and fluorodeoxyglucose [ 18 F] (FDG), we scanned rats at three time points: after thirteen weeks of treatment, after one week of abstinence, and after four weeks of abstinence. After thirteen weeks of LD and HD MP treatment, increases in brain glucose metabolism (BGluM) were seen in several cortical and subcortical regions associated with sensory and motor functions as well as learning and memory. One-week abstinence from LD MP treatment promoted increased BGluM compared to both water treated and HP MP treated groups. After four weeks of abstinence, little group differences were seen. Longitudinally, we observed contrasting differences on BGluM depending on whether a LD or HD of MP was administered. Our results demonstrate that MP treatment during adolescence can significantly alter BGluM. Moreover, these changes in brain activity do not subside in many areas of the brain after both one and four-week drug abstinence., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Apathy is a common and important yet often ignored neuropsychiatric symptom of Alzheimer's disease (AD). Cholinesterase inhibitors and memantine, used to treat AD, appear ineffective against apathy. A meta-analysis of 4 randomized, placebo-controlled trials (RCTs) found that psychostimulants significantly attenuated apathy ratings in AD. However, the pooled sample size in this meta-analysis was just 156, and one of the trials was a 2-week crossover study with a large effect. A large RCT (n = 200) has now been published. This study found that methylphenidate (MPH; 20 mg/d) was superior to placebo in the attenuation of apathy scores in patients with possible or probable, mild to moderate AD; the advantage was evident by the end of the second month of treatment and remained evident to the end of 6 months. The effect size at 6 months was small (Cohen d  = 0.37). In this RCT, disappointingly, MPH was not superior to placebo on secondary outcomes, including informant-rated apathy, dependence, activities of daily living, quality of life, and neurocognitive performance; caregiver burden was not formally studied. Speculatively, the psychosocial intervention provided to all participants in this RCT may have boosted response in the placebo group, thereby attenuating differences in outcomes between the MPH and placebo groups. A reasonable conclusion is that whereas MPH may attenuate the severity of apathy in patients with AD across as long as 6 months, the absence of improvements in measures of dependence, activities of daily living, and quality of life suggest that this effect of MPH on apathy may not be clinically significant. An unanswered question is whether the benefits of MPH may be clinically significant in real world practice settings in which the delivery of behavioral interventions is not feasible., (© Copyright 2022 Physicians Postgraduate Press, Inc.)

Background: Acute stress is thought to reduce goal-directed behaviour, an effect purportedly associated with stress-induced release of catecholamines. In contrast, experimentally increased systemic catecholamine levels have been shown to increase goal-directed behaviour. Whether experimentally increased catecholamine function can modulate stress-induced reductions in goal-directed behaviour and its neural substrates, is currently unknown., Aim: To assess whether and how experimentally induced increases in dopamine and noradrenaline contribute to the acute stress effects on goal-directed behaviour and associated brain activation., Methods: One hundred participants underwent a stress induction protocol (Maastricht acute stress test; MAST) or a control procedure and received methylphenidate (MPH) (40 mg, oral) or placebo according to a 2 × 2 between-subjects design. In a well-established instrumental learning paradigm, participants learnt stimulus-response-outcome associations, after which rewards were selectively devalued. Participants' brain activation and associated goal-directed behaviour were assessed in a magnetic resonance imaging scanner at peak cortisol/MPH concentrations., Results: The MAST and MPH increased physiological measures of stress (salivary cortisol and blood pressure), but only MAST increased subjective measures of stress. MPH modulated stress effects on activation of brain areas associated with goal-directed behaviour, including insula, putamen, amygdala, medial prefrontal cortex, frontal pole and orbitofrontal cortex. However, MPH did not modulate the tendency of stress to induce a reduction in goal-directed behaviour., Conclusion: Our neuroimaging data suggest that MPH-induced increases in dopamine and noradrenaline reverse stress-induced changes in key brain regions associated with goal-directed behaviour, while behavioural effects were absent. These effects may be relevant for preventing stress-induced maladaptive behaviour like in addiction or binge eating disorder.

Methylphenidate (MPH) is a psychostimulant, beneficial in attention deficit hyperactivity disorder (ADHD). Previously it has been shown that MPH-induced locomotor sensitization could be attenuate by buspirone co administration however the effect of chronic MPH and co-administration of MPH-buspirone on biochemical and hematological parameters are unknown. This study is designed to investigate these parameters after long term administration of MPH, Buspirone and their combination in rats. 40 male Wister rats were divided in to 4 groups, and treated with saline, MPH (2mg/kg/day), Buspirone (10mg/kg/day) and MPH-Buspirone co-administration (2mg/kg/day ±10mg/kg/day; respectively) up to six weeks. Administration of MPH significantly increase blood glucose level in saline treated control rats, however co-administration of MPH-buspirone exhibited less effect on blood glucose levels. Serum creatinine levels significantly decreased in all treated groups as compared to control but highly significant results were seen with combination treatment. Co-administration of MPH-buspirone and buspirone treated rats exhibited increased cholesterol and hemoglobin values. All treated groups showed increased values of hematocrit, MCV, MCH and MCHC compared to control group. RBCs and WBC's count were decreased in all treated groups. The platelet count rose significantly by Buspirone and MPH-buspirone administration, while MPH showed decreased platelet count. Thus, results suggested that prolong co-administration of MPH-buspirone is safe and effective for ADHD patients by preventing adverse effects not only on behavioral but also on biochemical and hematological parameter.

Introduction: This case illustrates the feasibility, benefit, and putative enhanced ecological validity of performing internet-parent-child interaction therapy (I-PCIT) in the parent-child dyad's home for the treatment of behavior problems in medically ill children in the context of a global pandemic., Patient Concerns: Parents of a 5-year-old girl initially presented with concerns regarding inattentiveness, physical and verbal fighting with her siblings, and getting kicked out of daycare for hitting another child. Patient also had difficulties sleeping at night., Diagnoses: Patient was diagnosed with electrical status epilepticus in sleep, frontal lobe executive function deficit, and attention deficit hyperactivity disorder., Interventions: Patient received a course of I-PCIT. Equipment included a cell phone with video capabilities connected to a videotelephony software program and set-up in the child's home by the parents. The treatment course included 8, 1-hour, weekly teaching/coaching sessions (7 of which were performed using I-PCIT) plus 1 follow-up booster session 6 months later., Outcomes: Home-based I-PCIT implementation greatly improved disruptive behaviors in a young child with electrical status epilepticus in sleep and attention deficit hyperactivity disorder., Conclusion: A combination of I-PCIT and methylphenidate allowed her to be successful at home and in a school setting. More research is needed on PCIT adaptations, such as home-based and internet-based PCIT, for medically ill children as well as treatment protocols for combined therapies., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Methylphenidate (MP) is combined with selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine (FLX) to treat various disorders. MP, a dopamine reuptake inhibitor, helps manage attention-deficit hyperactivity disorder (ADHD) and is abused as a cognitive enhancer; it has a reduced addiction liability. We showed that combining FLX (serotonin) with MP potentiates MP-induced gene regulation in the striatum. These studies used intraperitoneal drug administration, which is relevant for MP abuse. Clinically, MP and FLX are taken orally (slower bioavailability). Here, we investigated whether chronic oral administration of MP and FLX also altered striatal gene regulation. MP (30/60 mg/kg/day), FLX (20 mg/kg/day), and MP + FLX were administered in rats' drinking water for 8 h/day over 4 weeks. We assessed the expression of dynorphin and substance P (both markers for striatal direct pathway neurons) and enkephalin (indirect pathway) by in situ hybridization histochemistry. Chronic oral MP alone produced a tendency for increased dynorphin and substance P expression and no changes in enkephalin expression. Oral FLX alone did not increase gene expression. In contrast, when given together, FLX greatly enhanced MP-induced expression of dynorphin and substance P and to a lesser degree enkephalin. Thus, FLX potentiated oral MP-induced gene regulation predominantly in direct pathway neurons, mimicking cocaine effects. The three functional domains of the striatum were differentially affected. MP + SSRI concomitant therapies are indicated in ADHD/depression comorbidity and co-exposure occurs with MP misuse as a cognitive enhancer by patients on SSRIs. Our findings indicate that MP + SSRI combinations, even given orally, may enhance addiction-related gene regulation., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

BACKGROUNDCertain components of rest-activity rhythms such as greater eveningness (delayed phase), physical inactivity (blunted amplitude), and shift work (irregularity) are associated with increased risk for drug use. Dopaminergic (DA) signaling has been hypothesized to mediate the associations, though clinical evidence is lacking.METHODSWe examined associations between rhythm components and striatal D1 (D1R) and D2/3 receptor (D2/3R) availability in 32 healthy adults (12 female, 20 male; age 42.40 ± 12.22 years) and its relationship to drug reward. Rest-activity rhythms were assessed by 1-week actigraphy combined with self-reports. [11C]NNC112 and [11C]raclopride positron emission tomography (PET) scans were conducted to measure D1R and D2/3R availability, respectively. Additionally, self-reported drug-rewarding effects of 60 mg oral methylphenidate were assessed.RESULTSWe found that delayed rhythm was associated with higher D1R availability in caudate, which was not attributable to sleep loss or so-called social jet lag, whereas physical inactivity was associated with higher D2/3R availability in nucleus accumbens (NAc). Delayed rest-activity rhythm, higher caudate D1R, and NAc D2/3R availability were associated with greater sensitivity to the rewarding effects of methylphenidate.CONCLUSIONThese findings reveal specific components of rest-activity rhythms associated with striatal D1R, D2/3R availability, and drug-rewarding effects. Personalized interventions that target rest-activity rhythms may help prevent and treat substance use disorders.TRIAL REGISTRATIONClinicalTrials.gov: NCT03190954.FUNDINGNational Institute on Alcohol Abuse and Alcoholism (ZIAAA000550).

Methylphenidate (MPH) is a psychostimulant approved by the FDA to treatment Attention-Deficit Hyperactivity Disorder (ADHD). MPH is believed to exert its pharmacological effects via preferential blockade of the dopamine transporter (DAT) and the norepinephrine transporter (NET), resulting in increased monoamine levels in the synapse. We used a quantitative non-invasive PET imaging technique to study the effects of long-term methylphenidate use on the central nervous system (CNS). We conducted microPET/CT scans on young adult male rhesus monkeys to monitor changes in the dopaminergic system. We used [ 18 F] AV-133, a ligand for the vesicular monoamine transporter 2 (VMAT2), and [ 18 F]FESP a ligand for the D 2 and 5HT 2 receptors. In this study we evaluated the effects if chronic MPH treatment in the nonhuman primates (NHP). Two-year-old, male rhesus monkeys were orally administered MPH diluted in the electrolyte replenisher, Prang, twice a day, five days per week (M-F) over an 8-year period. The dose of MPH was gradually escalated from 0.15 mg/kg initially to 2.5 mg/kg/dose for the low dose group, and 1.5 mg/kg to 12.5 mg/kg/dose for the high dose group (Rodriguez et al., 2010). Scans were performed on Mondays, about 60 h after their last treatment, to avoid the acute effects of MPH. Tracers were injected intravenously ten minutes before microPET/CT scanning. Sessions lasted about 120 min. The Logan reference tissue model was used to determine the Binding Potential (BP) of each tracer in the striatum with the cerebellar cortex time activity curve as an input function. Both MP treatment groups had a lower [ 18 F] AV-133 BP, although this failed to reach statistical significance. MPH treatment did not have a significant effect on The BP of [ 18 F] FESP in the striatum. Long-term administration of MPH did not significant change any of the marker of monoamine function used here. These data suggest that, despite lingering concerns, long-term use of methylphenidate does not negatively impact monoamine function. This study also demonstrates that microPET imaging can distinguish differences in binding potentials of a variety of radiotracers in the CNS of NHPs. This approach may provide minimally-invasive biomarkers of neurochemical processes associated with chronic exposure to CNS medications. (Supported by NCTR)., (Published by Elsevier Inc.)

Purpose: To evaluate the effect of methylphenidate on visual field testing in healthy adults with abnormal visual field results., Methods: This prospective, randomized, controlled interventional clinical trial comprised all patients who had abnormal visual field test results and normal eye examination and ophthalmic history. Eligible patients were randomly assigned to either the study group or the control group. All patients repeated their visual field testing. Study group patients received a single dose of 10 mg methylphenidate prior to that. The main outcome measures were the percent difference in mean deviation and pattern standard deviation between the second and first visual fields., Results: The methylphenidate group had greater improvement in all parameters. Mean deviation improved by median 68% (IQR 19%-78%) in the methylphenidate group vs. 27% [-5% to 55%] in the controls. However, this was not statistically significant ( p = .83). Pattern standard deviation improved by median 49% (22%-59%) vs. 7% [-9% to 45%], respectively ( p = .012). The visual fields were also reviewed by 3 masked experienced ophthalmologists. They indicated that the second visual field improved in 76.2% of the methylphenidate group vs. 48.5% of the controls ( p = .04). A normal repeat visual field occurred in 57.7% vs. 21.2%, respectively. A subgroup analysis of patients with prior experience in visual field testing yielded an even more striking improvement in the methylphenidate group vs. controls., Conclusions: A single low dose of methylphenidate can improve visual field testing in subjects without ocular pathology, and even more in those with prior experience in perimetry.

Background: The process underlying the integration of perception and action is a focal topic in neuroscientific research and cognitive frameworks such as the theory of event coding have been developed to explain the mechanisms of perception-action integration. The neurobiological underpinnings are poorly understood. While it has been suggested that the catecholaminergic system may play a role, there are opposing predictions regarding the effects of catecholamines on perception-action integration., Methods: Methylphenidate (MPH) is a compound commonly used to modulate the catecholaminergic system. In a double-blind, randomized crossover study design, we examined the effect of MPH (0.25 mg/kg) on perception-action integration using an established "event file coding" paradigm in a group of n = 45 healthy young adults., Results: The data reveal that, compared with the placebo, MPH attenuates binding effects based on the established associations between stimuli and responses, provided participants are already familiar with the task. However, without prior task experience, MPH did not modulate performance compared with the placebo., Conclusions: Catecholamines and learning experience interactively modulate perception-action integration, especially when perception-action associations have to be reconfigured. The data suggest there is a gain control-based mechanism underlying the interactive effects of learning/task experience and catecholaminergic activity during perception-action integration., (© The Author(s) 2021. Published by Oxford University Press on behalf of CINP.)

Background: Children and adolescents with attention deficit hyperactivity disorder (ADHD) are at higher risk of all-cause poisoning by drugs and chemicals (intentional or accidental). Currently, there is limited data on whether medication treatment for ADHD can reduce the risk of all-cause poisoning., Methods: Patients aged 5-18 years with a methylphenidate (MPH) prescription and an incident poisoning diagnosis between January 2001 and June 2020 were identified from the Hong Kong Clinical Data Analysis and Reporting System. A self-controlled case series study design was used to compare the incidence rate ratios (IRRs) of all-cause poisoning during different risk windows (30 days before the first MPH prescription, exposure periods within 30 days of the first prescription, and periods of subsequent exposure) compared with the reference window (other non-exposure periods)., Results: 42,203 patients were prescribed ADHD medication in Hong Kong during the study period. Of these, 417 patients who had both an MPH prescription and poisoning incident recorded were included in the main analysis. Compared with other non-exposed periods, a higher risk of poisoning was found in the 30 days before the first prescription (IRR 2.64, 95% confidence interval [CI] 1.33-5.22) and exposure periods within 30 days of the first prescription (IRR 2.18, 95% CI 1.06-4.48), but not during prolonged exposure. However, compared with 30 days before the first prescription as well as exposure periods within 30 days of the first prescription, there was a lower risk during the subsequent exposure (IRRs 0.49 and 0.60, respectively). Similar results to the main analysis were also found in the subgroup analysis of intentional poisoning and females, but not in that of accidental poisoning and males., Conclusions: The risk of all-cause poisoning was higher shortly before and after the first MPH prescription and became lower during the subsequent prescription period. Our results do not support an association between the use of MPH and an increased risk of all-cause poisoning in children and adolescents and, in fact, suggest that longer-term use of MPH may be associated with a lower risk of all-cause poisoning, although this latter finding requires further study., (© 2021. The Author(s).)

Objective: Delayed-release and extended-release methylphenidate (DR/ER-MPH), the first stimulant predicted to be absorbed primarily in the colon, demonstrated significant improvements in attention-deficit/hyperactivity disorder (ADHD) symptoms and functional impairment from awakening until evening versus placebo in clinical trials. The clinical significance of these improvements was explored post hoc by examining response and remission thresholds as well as safety in the context of dose optimization., Methods: Data from the open-label, treatment-optimization phase of a phase 3 study of DR/ER-MPH in children (aged 6-12 years) with ADHD, as diagnosed by DSM-5 criteria and enrolled between July 2015 and March 2016, were analyzed. Thresholds for response (anchored to Clinical Global Impressions-Improvement scale [CGI-I] score of 1 or 2) and remission were applied to ADHD Rating Scale-IV (ADHD-RS-IV), Before School Functioning Questionnaire (BSFQ), and Parent Rating of Evening and Morning Behavior, Revised, Morning Subscale (PREMB-R AM) and Evening Subscale (PREMB-R PM) scores. Rates of response, remission, and treatment-emergent adverse events by starting dose were examined., Results: Mean DR/ER-MPH dose increased from 29.7 mg/d at baseline (51% on 20 mg/d; 49% on 40 mg/d) to 66.2 mg/d at week 6. At week 6, most participants achieved response/remission thresholds (response/remission: ADHD-RS-IV: 97%/89%; BSFQ: 98%/94%; PREMB-R AM: 94%/98%; PREMB-R PM: 91%/84%). More participants starting on a 40-mg versus 20-mg dose achieved thresholds at week 1 ( P  < .02). Weekly treatment-emergent adverse event rates over the open-label period were similar between starting doses., Conclusions: When DR/ER-MPH dosing was optimized for ADHD symptom control throughout the day, the majority of participants achieved thresholds indicating all-day control of ADHD symptoms and functional impairment to the level of their non-ADHD peers., Trial Registration: Data used in this post hoc analysis came from the study with ClinicalTrials.gov identifier: NCT02493777., (© Copyright 2021 Physicians Postgraduate Press, Inc.)

Methylphenidate (MPD) is used as a first-line treatment for attention-deficit/hyperactivity disorder (ADHD). The number of prescriptions for ADHD patients is increasing, suggesting that the number of fertile women using such medication might be also increasing. The purpose of this study was to clarify the effects of MPD exposure during the fetal period on infant development, behavior, learning, and memory in mice. Expression levels of candidate genes associated with ADHD were also determined in the brain of pups born to MDP-treated dams who were administered MPD orally at a dose of 2.5, 7.5, or 15 mg/kg daily from gestational day 1 to the day before delivery. Offspring aged 6-8 weeks were subjected to the spontaneous locomotor activity, elevated plus-maze, and passive avoidance tests and therapeutic treatments with MPD or atomoxetine. Fetal MPD exposure induced ADHD-like phenotypes, such as hyperactivity and impulsivity, in mouse offspring, which were suppressed by treatment with MPD and atomoxetine. These mice showed decreased Drd2 and Slc6a3 expression levels in the brain, which are often observed in ADHD model animals. Our results suggest that continuous use of MPD during pregnancy induces ADHD phenotypes in the offspring., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: The effects of stimulant treatment on sleep in adults with attention-deficit/hyperactivity disorder (ADHD) are complex and varied, with some individuals experiencing worsening of sleep but others experiencing improvement., Methods: Data from previously reported trials of the clinical efficacy and safety of the long-acting methylphenidate formulation PRC-063 (Adhansia XR ® in the USA; Foquest ® in Canada) in adults with ADHD were used to evaluate patient-reported sleep outcomes, as captured using the Pittsburgh Sleep Quality Index (PSQI) and adverse events of insomnia. The trials comprised 4 weeks of randomized, forced-dose PRC-063 treatment at a dose of 0 (placebo), 25, 45, 70, or 100 mg/day followed by an optional 6 months of open-label PRC-063 treatment at an individually optimized dose of 25-100 mg/day., Results: At the end of double-blind treatment, PRC-063 (all doses combined; N = 297) showed no significant difference versus placebo (N = 78) in least squares mean change in global PSQI score from baseline (- 0.7 vs. - 1.3; P = 0.0972) or in scores for each of the seven subscales of the PSQI. For patients enrolled in the open-label extension (N = 184), mean ± standard deviation global PSQI score improved from 7.8 ± 3.55 at the end of double-blind treatment to 5.8 ± 3.11 at 1 month and 5.4 ± 3.21 at 6 months (P < 0.0001). A greater proportion of patients were good sleepers (global PSQI score ≤ 5) at the end of the open-label extension (57.3%) than at baseline (20.9%) or at the end of double-blind treatment (26.0%). In a logistic regression analysis, baseline global PSQI score (odds ratio 1.491; P < 0.0001), but not randomized study treatment (P = 0.1428), was a significant predictor of poor sleep (global PSQI score > 5) at the end of double-blind treatment. Adverse event rates for insomnia (15.8 vs. 3.8%) and initial insomnia (6.1 vs. 1.3%) during double-blind treatment were higher for PRC-063 (all doses combined) than for placebo. Two patients receiving PRC-063 in the double-blind study and one patient in the open-label study were withdrawn because of insomnia adverse events., Conclusions: Our findings indicate that, on average, PRC-063 had no significant impact on overall sleep quality in adults with ADHD. Although insomnia was observed as an adverse event, when sleep was measured over time as an outcome in its own right for patients receiving dose-optimized PRC-063 open-label, more patients showed improvement in sleep than deterioration. CLINICALTRIALS., Gov Identifer: NCT02139124 and NCT02168127.

Purpose/background: This study aimed to evaluate the frequency of needing to switch the initial treatment of a stimulant to the alternative family in newly referred, medication-naive adults with attention-deficit/hyperactivity disorder (ADHD) initiating treatment with stimulants., Methods/procedures: Subjects were 49 unmedicated adults (18-45 years old) with Diagnostic and Statistical Manual of Disorders (Fifth Edition) ADHD who initiated treatment with a stimulant. Before the clinical assessment with an expert clinician, participants completed the Adult Self-Report, Behavior Rating Inventory of Executive Function-Adult Version, Emotional Dysregulation Subscale of the Barkley Current Behavior Scale-Self-report, and Mind Wandering Questionnaire. The rate of switching was examined using information from the electronic medical record for up to three clinical follow-up visits. Comparisons were made between those who did and did not need to switch on baseline demographic and clinical characteristics., Findings/results: Sixty-seven percent of ADHD patients were initially prescribed a methylphenidate product, and 33%, an amphetamine product. Forty-one percent of ADHD patients needed to switch from their initially prescribed stimulant family within 90 days of initiating treatment because of poor tolerability. Whereas the rate of switching was significantly higher in those initially prescribed methylphenidate, the rate of patients who required changes in formulation (long- to short-acting and vice versa) or additional antianxiety or antidepressant treatment ("strugglers") was higher in those taking amphetamine. Switchers were more impaired on the Adult Self-Report Intrusive scale, whereas nonswitchers were more impaired on the Behavior Rating Inventory of Executive Function Inhibit and Task Monitor scales. However, these findings were small and of unclear clinical significance., Implications/conclusions: Forty-one percent of medication-naive adults with ADHD initiating stimulant treatment required a switch from the initially prescribed stimulant family to the alternative one because of poor tolerability. Switching could not be adequately predicted by baseline demographic or clinical characteristics. These findings call for improved efforts to help identify predictors of response to stimulant treatment in adults with ADHD to avoid unnecessary delays in identifying a safe and effective treatment for these patients., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Dopamine activity can modulate physical performance in the heat, but less is known about its effects on cognition during thermal stress. Twelves males completed a randomized, double-blinded protocol consisting of oral ingestion of 20 mg of methylphenidate (MPH) or placebo (lactose pill) during passive heating using a water-perfused suit (water temperature ∼49 °C). To identify the impact of peripheral versus central thermal strain, a cognitive test battery was completed at 4 different thermal states: baseline (BASE; 37.2 ± 0.6 °C core, 32.9 ± 0.7 °C skin), neutral core-hot skin (NC-HS; 37.2 ± 0.3 °C, 37.4 ± 0.3 °C), hyperthermic core-hot skin (HC-HS; 38.7 ± 0.4 °C, 38.7 ± 0.2 °C), and hyperthermic core-cooled skin (HC-CS; 38.5 ± 0.4 °C, 35.1 ± 0.8 °C). The cognitive test battery consisted of the 2-back task (i.e., working memory), set-shifting (i.e., executive function), Groton Maze Learning Task (i.e., executive function) and detection task (i.e., psychomotor processing). MPH led to significantly higher heart rates (∼5-15 b·min -1 ) at BASE, NC-HS, and HC-HS (all p < 0.05). There were no significant differences in the number of errors made on each task (all p < 0.05). Participants were significantly faster ( p < 0.05) on the set-shifting task in the HC-HS timepoint, irrespective of drug condition ( p > 0.05). In summary, we demonstrated that 20 mg of MPH did not significantly alter cognitive function during either normothermia or moderate hyperthermia. Novelty: Twenty milligrams of MPH did not significantly alter cognitive function during passive heat stress. MPH led to significant higher heart rates (∼5-15 b·min -1 ) in thermoneutral and during passive heat stress. Future studies are needed to determine the mechanisms of why MPH improves physical but not cognitive performance during heat stress.

Evidence is emerging that fathers can have nongenetic effects on the phenotypes of their offspring. Most studies have focused on the role that nongenetic modifications to sperm can have on offspring phenotype; however, fathers can also have nongenetic effects on offspring through their interactions with females, called female-mediated paternal effects. These effects can occur in situations where male phenotype, e.g. behaviour or morphology, affects female stress and/or provisioning of offspring. These effects are potentially widespread, but few studies have explicitly investigated the role of female-mediated paternal effects on offspring phenotype. Here, we asked if male mating interactions can affect offspring via female mediated paternal effects in the Trinidadian guppy, Poecilia reticulata. To do this, we manipulated mating behaviour by: (i) administering a drug known to affect the neurotransmitter dopamine, and (ii) varying the familiarity of potential mates, which affects attractiveness in this species. With these treatments, we successfully manipulated the mating behaviour of male guppies and female preference for those males. Further, we found significant effects of sire mating behaviour, sire drug treatment, and parental familiarity status on behavioural measures of offspring anxiety in response to a novel object. Because Control offspring of 'familiar' and 'unfamiliar' pairs differed in their behaviour, our results cannot be solely attributed to potential nongenetic modifications to sperm caused by the drug. These results emphasize the importance of female-mediated paternal effects, including those caused by altered male mating behaviour, in shaping offspring phenotype., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Methylphenidate (MPH) is a psychostimulant widely misused to increase wakefulness by drivers and students. Also, MPH can be found in dietary supplements in a clandestine manner aiming to burst performance of physical exercise practitioners. The abusive use of high doses of caffeine (CAF) in these contexts is equally already known. Here, we demonstrate the behavioral, oxidative and mitochondrial effects after acute exposure to high doses of MPH (80 mg/L) and CAF (150 mg/L), alone or associated (80 mg/L + 150 mg/L, respectively). We used zebrafish as animal model due to its high translational relevance. We evaluated the behavioral effects using the Novel Tank Test (NTT), Social Preference Test (SPT) and Y-maze Task and analyzed biomarkers of oxidative stress and activity of mitochondrial respiratory chain complexes. MPH alone induced antisocial behavior. MPH inhibited lipid peroxidation. The association of MPH + CAF presented memory impairment and anxiogenic behavior. In oxidative status, it inhibited lipid peroxidation, increased protein carbonylation and mitochondrial complex II, III and IV activity. Our results demonstrate that MPH and CAF alone negatively impact the typical behavioral of zebrafish. When associated, changes in cognition, memory, oxidative and mitochondrial status are more relevant., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Aim: To assess the empirical evidence for the treatment of attention deficit/hyperactivity disorder (ADHD) in populations with autism spectrum disorder (ASD)., Methods: A systemic PubMed, PsychINFO, Embase, and Medline database search of peer-reviewed literature was conducted. Included in the review were controlled trials published in English with sample sizes ⩾10 participants examining the safety and efficacy of anti-ADHD medication in ASD populations. Data was extracted on relevant variables of study design, demographics, associated psychopathology, medication dose, efficacy, and tolerability., Results: Nine controlled trials met the inclusion and exclusion criteria: five with methylphenidate, three with atomoxetine, and one with guanfacine. Sample sizes ranged from 10 to 128 with 430 children participating across all the trials. In all the trials, treatment response was significantly superior to placebo. However, almost all trials assessed only hyperactivity, and most included only participants with intellectual disability with high levels of irritability. None of the trials distinguished agitation from hyperactivity. The response on hyperactivity for methylphenidate and atomoxetine was less than that observed in the neurotypical population; however, the response for guanfacine surpassed results observed in neurotypical populations. Treatment-emergent mood lability (i.e. mood dysregulation and mood-related adverse events) was frequently associated with methylphenidate and guanfacine treatments. Worse treatment outcomes were associated with individuals with lower intellectual capability compared with those with higher IQs., Conclusions: here is a scarcity of controlled trials examining ADHD treatments in ASD populations, particularly in intellectually capable individuals with ASD and in adults. Response to ADHD medications in ASD were adversely moderated by the presence of intellectual disability and mood lability.