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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. [ABSTRACT FROM AUTHOR]

Background: Methamphetamine is frequently co-consumed with alcohol, yet combined effects on visually guided behaviours have not been experimentally assessed. This study examined whether methamphetamine and alcohol-induced changes in gaze behaviour can be accurately detected and indexed during a simulated driving task to establish characteristic patterns relevant to traffic safety. Methods: In a randomised, placebo-controlled, cross-over study design, the effects of acute oral methamphetamine (0.42 mg/kg) were assessed with and without low doses of alcohol (target 0.04% blood alcohol content) on gaze behaviour during driving. Twenty healthy adults (mean age 29.5 years (SD ± 4.9), 40% female) completed four, 1-h simulated drives with simultaneous eye monitoring using the SensoMotoric Instruments cap-mounted eye tracker over a 4-week experimental paradigm. Gaze entropy measures were used to quantify visual scanning efficiency, expressed as gaze transition entropy and stationary gaze entropy. Fixations, recorded as duration (milliseconds, ms) and rate (count) per minute, were examined in 10-min bins over the duration of the drive. Driving performance was assessed by the standard deviation of lateral position, standard deviation of speed and steering variability. Results: Methamphetamine increased the rate and duration of fixations and produced a less dispersed but more disorganised pattern of gaze during highway driving while preserving performance. Alcohol alone impaired both oculomotor control and driving performance, even when consumed at levels well below the legal limit stipulated in many international jurisdictions. Conclusions: Methamphetamine-affected drivers display inefficient exploration in a limited visual range during driving. Eye-tracking metrics thus show potential for indexing intoxication due to psychoactive substance usage. [ABSTRACT FROM AUTHOR]

A set of interventions that can produce altered states of consciousness (ASC) have shown utility in the treatment of substance misuse. In this review, we examine addiction-related outcomes associated with three common interventions that produce ASCs: psychedelic-assisted psychotherapy (PP), Transcendental Meditation (TM) and hypnotherapy (HT). While procedurally distinct, all three interventions are associated with some common phenomenological, psychological, and neurobiological features, indicating some possible convergent mechanisms of action. Along with addiction and mental health outcomes, these common features are reviewed, and their impact on substance misuse is discussed. While our review highlights some mixed findings and methodological issues, results indicate that PP and TM are associated with significant improvements in substance misuse, alongside improvements in emotional, cognitive and social functioning, behavior-change motivation, sense of self-identity, and meaning. In contrast, and despite its broader acceptance, HT has been associated with mixed and minimal results with respect to substance misuse treatment. Authors identify key research gaps in the role of ASC interventions in addiction and outline a set of promising future research directions. [ABSTRACT FROM AUTHOR]

Driving is a critical everyday task necessitating the rapid and seamless integration of dynamic visually derived information to guide neurobehaviour. Biological markers are frequently employed to detect Δ9‐tetrahydrocannabinol (THC) consumption among drivers during roadside tests, despite not necessarily indicating impairment. Characterising THC‐specific alterations to oculomotor behaviour may offer a more sensitive measure for indexing drug‐related impairment, necessitating discrimination between acute THC effects, chronic use and potential tolerance effects. The present review aims to synthesise current evidence on the acute and chronic effects of THC on driving‐relevant oculomotor behaviour. The review was prospectively registered (10.17605/OSF.IO/A4H9W), and Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines informed reporting standards. Overall, 20 included articles comprising 12 experimental acute dosing trials, 5 cross‐sectional chronic use studies and 3 roadside epidemiological studies examined the effects of cannabis/THC on oculomotor parameters including saccadic activity gaze behaviour, nystagmus, smooth pursuit and eyelid/blink characteristics. Acute THC consumption selectively impacts oculomotor control, notably increasing saccadic latency and inaccuracy and impairing inhibitory control. Chronic cannabis users, especially those with early age of use onset, display enduring oculomotor deficits that affect visual scanning efficiency. The presence of eyelid tremors appears to be a reliable indicator of cannabis consumption while remaining distinct from direct impairment associated with visual attention and motor control. Cannabis selectively influences oculomotor activity relevant to driving, highlighting the role of cannabinoid systems in these processes. Defining cannabis/THC‐specific changes in oculomotor control may enhance the precision of roadside impairment assessments and vehicle safety systems to detect drug‐related impairment and assess driving fitness. [ABSTRACT FROM AUTHOR]

Sleep problems, depression, and anxiety are highly prevalent after a spinal cord injury (SCI) and traumatic brain injury (TBI) and may worsen functional outcomes and quality of life. This scoping review examined the existing literature to understand the relationships between sleep quality, depression, and anxiety in persons with SCI and TBI, and to identify gaps in the literature. A systematic search of seven databases was conducted. The findings of 30 eligible studies reporting associations between sleep quality and depression and/or anxiety after SCI or TBI were synthesized. The included studies were mostly cross-sectional and employed a range of subjective and objective measures of sleep quality. Poor subjective sleep quality and insomnia tended to be significantly associated with increased levels of depression and/or anxiety, but no such associations were reported when sleep quality was measured objectively. Two longitudinal studies observed worsening depressive symptoms over time were related to insomnia and persistent sleep complaints. Two interventional studies found that treating sleep problems improved symptoms of depression and anxiety. The findings of this review suggest that sleep and psychopathology are related in persons with neurotraumatic injuries. This has important therapeutic implications, because individuals may benefit from therapy targeting both sleep and psychological issues. More longitudinal and interventional studies are warranted to further understand the direction and strength of the relationships and how they impact patient outcomes. [ABSTRACT FROM AUTHOR]