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Background This study examined the effects of atomoxetine ( ATX) and OROS methylphenidate ( MPH) on laboratory measures of inhibitory control and attention in youth with attention-deficit/hyperactivity disorder ( ADHD). It was hypothesized that performance would be improved by both treatments, but response profiles would differ because the medications work via different mechanisms. Methods One hundred and two youth (77 male; mean age = 10.5 ± 2.7 years) with ADHD received ATX (1.4 ± 0.5 mg/kg) and MPH (52.4 ± 16.6 mg) in a randomized, double-blind, crossover design. Medication was titrated in 4-6-week blocks separated by a 2-week placebo washout. Inhibitory control and attention measures were obtained at baseline, following washout, and at the end of each treatment using Conners' Continuous Performance Test II ( CPT- II), which provided age-adjusted T-scores for reaction time ( RT), reaction time variability ( RT variability), and errors. Repeated-measures analyses of variance were performed, with Time (premedication, postmedication) and Treatment type ( ATX, MPH) entered as within-subject factors. Data from the two treatment blocks were checked for order effects and combined if order effects were not present. Clinical trial registration: Clinicaltrials.gov: NCT00183391. Results Main effects for Time on RT ( p = .03), RTSD ( p = .001), and omission errors ( p = .01) were significant. A significant Drug × Time interaction indicated that MPH improved RT, RTSD, and omission errors more than ATX ( p < .05). Changes in performance with treatment did not correlate with changes in ADHD symptoms. Conclusions MPH has greater effects than ATX on CPT measures of sustained attention in youth with ADHD. However, the dissociation of cognitive and behavioral change with treatment indicates that CPT measures cannot be considered proxies for symptomatic improvement. Further research on the dissociation of cognitive and behavioral endpoints for ADHD is indicated. [ABSTRACT FROM AUTHOR]

Stimulant medications, such as methylphenidate (MPH), are the most commonly used, effective treatment for ADHD. MPH acts primarily by inhibiting the dopamine transporter (DAT), a protein responsible for the reuptake of dopamine from the synapse into presynaptic terminals. We sought to evaluate the relationship between DATI 3'-untranslated region (3'-UTR) variable number tandem repeats (VNTR) genotypes and dose response to MPH. Children with ADHD (n = 47), ages 5-16 years (mean = 9.07 years), underwent a 4-week, double-blinded, crossover trial with forced weekly dosage changes. Children were genotyped for the DATI VNTR and evaluated on placebo and three dosage levels of OROS® MPH. Parents and clinicians who were blind to genotype and medication status rated ADHD symptoms, impairment, and stimulant side effects each week. Children who were homozygous for the less common, 9repeat DATI 3'-UTR genotype displayed a distinct dose-response curve from that of the other genotype groups, with an absence of typical linear improvement when the dose was increased from 18 mg to 36 and 54 mg. Further research is needed to determine the mechanisms related to poor response in patients with the 9/9-repeat genotype, and to determine if this group responds differentially to alternative treatments. [ABSTRACT FROM AUTHOR]

Objective. OROS methylphenidate HCL (MPH) is a recently developed long-acting stimulant medication used to treat attention-deficit/hyperactivity disorder (ADHD). This study was conducted to examine dosage effects on ADHD symptoms and stimulant side effects and to explore potential moderating effects of ADHD subtype. Methods. Children with ADHD combined type (ADHD-CT) or predominantly inattentive type (ADHD-PI; n = 47), ages 5 to 16 years, underwent a placebo-controlled, crossover trial using forced titration with weekly switches at 3 dosage levels. Parent and teacher ratings of ADHD symptoms were used to evaluate efficacy. In addition, vital signs and standardized measures of stimulant side effects were obtained weekly. Results. Parent ratings were more sensitive to treatment effects than teacher ratings. ADHD symptoms and Clinical Global Impressions Severity Index ratings at each dose condition differed significantly from placebo and baseline ratings, which did not differ from one another. For those with ADHD-CT, there was a clear linear dose-response relationship, with clinically significant reductions in ADHD Rating Scale-IV scores occurring in two thirds to three fourths of the subjects during either 36- or 54-mg dose conditions. Children with ADHD-PI, conversely, were more likely to respond optimally to lower doses and derived less benefit from higher doses, with 60% displaying significant improvement on the ADHD Rating Scale-IV at 36 mg or lower. Mild stimulant side effects were reported during placebo and at all dosage levels. With the exception of insomnia and decreased appetite, which were more common at higher... [ABSTRACT FROM AUTHOR]

Evaluates the short-term efficacy and side effects associated with two methylphenidate hydrochloride (MPH) dosing patterns. Thrice a day dosing as the optimum treatment for must children with attention deficit hyperactivity disorder (ADHD); Severity and time course of ADHD symptoms as the basis of dosing schedule.

Reflecting on the accompanying article by Jans et al., we draw the following thoughts. Future research on multiplex ADHD families is needed to elucidate mechanisms, timing, and a sequencing of interventions, preferably in treatment naïve participants. Furthermore, in addition to symptom measures, it is likely that multi‐informant measures of functional impairments such as parenting and parent‐child observations may help elucidate the complex mechanisms linking maternal and child ADHD, and eventually lead to more targeted, efficient, and feasible prevention and intervention strategies. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to compare the short-term efficacy, tolerability, and 1-year adherence in Chinese children and adolescents with attention-deficit/hyperactivity disorder (ADHD) treated with either osmotic release oral system methylphenidate (OROS MPH) or atomoxetine (ATX).Methods: Children and adolescents meeting Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV) criteria for ADHD were randomly assigned to receive either OROS MPH (n = 119) or ATX (n = 118). Participants underwent a 1-4 week dose titration period to determine optimal dose, and then were maintained on that dose for 4 weeks (maintenance period). Assessment for efficacy was conducted every week over the titration period and at the end of the maintenance period. The primary efficacy measure was the investigator-rated total ADHD Rating Scale-IV (ADHD-RS-IV) score. Response was further classified as remission (ADHD-RS-IV [18 or 9 items] average score ≤1), robust improvement (ADHD-RS-IV ≥40% decrease in total score), or improvement (≥ 25% decrease in total score) at the end of maintenance period. Medication adherence (taking medication at least 5 days in 1 week) and reasons for nonadherence were evaluated every week over the titration period, at the end of maintenance period, and then at 3, 6, and 12 months.Results: At the end of maintenance period, both OROS MPH and ATX were associated with significant and similar reductions from baseline in ADHD symptoms. Percentages achieving remission, robust improvement, and improvement were comparable for OROS MPH and ATX treatment (35.3% vs. 37.1%, 45.4% vs. 44.8%, 65.5% vs. 66.4%). Medication use decreased over time for both treatments; however, at end of maintenance period, 3 month, 6 month, and 1 year follow-ups, subjects in the OROS MPH group were more likely to be compliant with treatment (74.8%, 50.4%, 38.7%, and 21.8% for OROS MPH vs. 52.5%, 33.9%, 12.7%, and 3.4% for ATX) ( p < 0.05). The most common reasons for nonadherence were adverse events and lack of efficacy.Conclusions: Both OROS MPH and ATX resulted in similar reductions in ADHD symptoms in Chinese children and adolescents with ADHD. Long-term adherence with medication was poor in general, although somewhat better with OROS MPH than with ATX.Clinical Trial Registration: ClinicalTrials.gov , Identifier: NCT01065259. [ABSTRACT FROM AUTHOR]

Objective: Few treatment studies of attention-deficit/hyperactivity disorder (ADHD) extend beyond a few months. This article reports an interim analysis of a 24-month study evaluating the 12-month tolerability and effectiveness of a once-daily OROS® formulation of methylphenidate (OROS MPH) in children with ADHD. Method: Children, aged 6-13 years, with ADHD who participated in previous controlled studies and were MPH responders, received once-daily OROS MPH in this multicenter, open-label, nonrandomized study. Effectiveness was evaluated monthly by parents/caregivers and schoolteachers using validated rating scales (e.g., IOWA Conners). Safety and adverse events assessments involved objective (e.g., vital signs, growth) and subjective (sleep quality, tics) reporting. Results: Seventy-one percent of subjects (289/407) completed 12 months' treatment. Effectiveness was maintained throughout 12 months as demonstrated by stable IOWA Conners ratings and sustained improvements in peer interaction and Global Assessment Scale scores. OROS MPH was well tolerated, with adverse events similar to those expected with short-acting stimulant medication. OROS MPH had minimal impact on sleep quality and tics. There were no clinically meaningful changes in blood pressure, pulse, or height. The apparent absence of meaningful changes is tempered by the fact that children were MPH responders and were medicated at baseline, most for extended periods prior to enrollment. Conclusion: In this open-label study, once-daily OROS MPH treatment appears to be well tolerated and effectiveness was maintained for up to 12 months in these children with ADHD. J. Am. Acad. Child Adolesc. Psychiatry, 2003, 42(4):424-433. [ABSTRACT FROM AUTHOR]

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that has become increasingly prevalent worldwide. Its core symptoms, including difficulties regulating attention, activity level, and impulses, appear in early childhood and can persist throughout the lifespan. Current pharmacological options targeting catecholamine neurotransmissions have effectively alleviated symptoms in some, but not all affected individuals, leaving clinicians to implement trial-and-error approach to treatment. In this review, we discuss recent experimental evidence from both preclinical and human studies that suggest imbalance of excitation/inhibition (E/I) in the fronto-striatal circuitry during early development may lead to enduring neuroanatomical abnormality of the circuitry, causing persistence of ADHD symptoms in adulthood. We propose a model of precision medicine care that includes E/I balance as a candidate biomarker for ADHD, development of GABA-modulating medications, and use of magnetic resonance spectroscopy and scalp electrophysiology methods to monitor the effects of treatments on shifting E/I balance throughout the lifespan. [ABSTRACT FROM AUTHOR]

Attention deficit/hyperactivity disorder (ADHD) symptoms are common in youth with autism spectrum disorders (ASD) and are frequently treated with stimulant medications. Twenty-seven children were randomized to different dose titration schedules, and ADHD symptoms, tolerability, and aberrant behaviors were assessed weekly during a 6-week trial with long-acting liquid methylphenidate (MPH). MPH at low to moderate doses was effective in reducing ADHD symptoms and was well tolerated in young children with ASD and ADHD. Future studies are needed to assess generalization and maintenance of efficacy. [ABSTRACT FROM AUTHOR]

Objective: Because of significant individual variability in attention-deficit/hyperactivity disorder (ADHD) medication response, there is increasing interest in identifying genetic predictors of treatment effects. This study examined the role of four catecholamine-related candidate genes in moderating methylphenidate (MPH) dose-response.Method: Eighty-nine stimulant-naive children with ADHD 7 to 11 years old participated in a randomized, double-blind, crossover trial of long-acting MPH. Parents and teachers assessed each child's response on placebo and three MPH dosage levels using the Vanderbilt ADHD rating scales. Children were genotyped for polymorphisms in the 3' untranslated region of dopamine transporter (DAT), exon 3 on dopamine receptor D(4) (DRD4), codon 158 on catechol-O-methyltransferase, and the adrenergic α(2A)-receptor promoter. Linear mixed models evaluated gene, dose (milligrams per kilogram per day), and gene-by-dose effects on inattentive and hyperactive-impulsive domain outcomes.Results: The most statistically significant gene-by-dose interactions were observed on hyperactive-impulsive symptoms for DRD4 and DAT polymorphisms, with participants lacking the DAT 10-repeat allele showing greater improvements in symptoms with increasing dose compared with 10-repeat carriers (p = .008) and those lacking the DRD4 4-repeat allele showing less improvement across MPH doses compared with 4-repeat carriers (p = 0.02).Conclusions: This study suggests that DAT and DRD4 polymorphisms may be associated with individual variability in MPH dose-response, although further research in larger samples is required to confirm these findings and their clinical utility.Clinical Trial Registration Information: Response Variability in Children with Attention-Deficit/Hyperactivity Disorder (ADHD); http://www.clinicaltrials.gov; NCT01238822. [ABSTRACT FROM AUTHOR]

Objective: Methylphenidate has prominent effects in the dopamine-rich striatum that are absent for the selective norepinephrine transporter inhibitor atomoxetine. This study tested whether baseline striatal activation would predict differential response to the two medications in youth with attention-deficit/hyperactivity disorder (ADHD).Method: A total of 36 youth with ADHD performed a Go/No-Go test during functional magnetic resonance imaging at baseline and were treated with methylphenidate and atomoxetine using a randomized cross-over design. Whole-brain task-related activation was regressed on clinical response.Results: Task-related activation in right caudate nucleus was predicted by an interaction of clinical responses to methylphenidate and atomoxetine (F1,30 = 17.00; p < .001). Elevated caudate activation was associated with robust improvement for methylphenidate and little improvement for atomoxetine. The rate of robust response was higher for methylphenidate than for atomoxetine in youth with high (94.4% vs. 38.8%; p = .003; number needed to treat = 2, 95% CI = 1.31-3.73) but not low (33.3% vs. 50.0%; p = .375) caudate activation. Furthermore, response to atomoxetine predicted motor cortex activation (F1,30 = 14.99; p < .001).Conclusion: Enhanced caudate activation for response inhibition may be a candidate biomarker of superior response to methylphenidate over atomoxetine in youth with ADHD, purportedly reflecting the dopaminergic effects of methylphenidate but not atomoxetine in the striatum, whereas motor cortex activation may predict response to atomoxetine. These data do not yet translate directly to the clinical setting, but the approach is potentially important for informing future research and illustrates that it may be possible to predict differential treatment response using a biomarker-driven approach.Clinical Trial Registration Information: Stimulant Versus Nonstimulant Medication for Attention Deficit Hyperactivity Disorder in Children; https://clinicaltrials.gov/; NCT00183391. [ABSTRACT FROM AUTHOR]