SUMMARYIn the present study, we assessed the effects of regular use of methylphenidate medication in children diagnosed with attention deficit hyperactivity disorder (ADHD) on sleep timing, duration and sleep architecture. Twenty-seven children aged 6-12 years meeting diagnostic criteria for Diagnostic and Statistical Manual version IV ADHD and 27 control children matched for age (±3 months) and gender. Two nights of standard polysomnographic (PSG) recordings were conducted. ADHD children were allocated randomly to an on-or 48 h off-methylphenidate protocol for first or second recordings. Control childrenÕs recordings were matched for night, but no medication was used.Mixed modelling was employed in the analyses so that the full data set was used to determine the degree of medication effects. Methylphenidate in ADHD children prolonged sleep onset by an average of 29 min [confidence interval (CI) 11.6, 46.7], reduced sleep efficiency by 6.5% (CI 2.6, 10.3) and shortened sleep by 1.2 h (CI 0.65, 1.9). Arousal indices were preserved. Relative amounts of stages 1, 2 and slow wave sleep were unchanged by medication. Rapid eye movement sleep was reduced ()2.4%) on the medication night, an effect that became non-significant when control data were incorporated in the analyses. PSG data from ADHD children off-medication were similar to control data. Our findings suggest that methylphenidate reduces sleep quantity but does not alter sleep architecture in children diagnosed with ADHD.

ABSTRACT:The objective of this study was to quantify behavioral and attention capacity changes in children aged 4 -11 y before and 3 mo after adenotonsillectomy (A/T). Overnight cardiorespiratory recordings were performed in 61 "behaviorally normal" children 1 wk before A/T. Tests of sustained attention using visual and auditory continuous performance tests (CPT) were completed by children 1 wk before and 3 mo after A/T. Behavioral Assessment Scales for Children (BASC) and a sleep questionnaire were completed by the parent/s at these same times. Results from overnight cardiorespiratory recordings showed that the children had mild sleeprelated breathing disorders (SRBD) preoperatively with a mean apnea/hypopnea index of 3.0/h and a movement awakening index of 2.5/h. The majority had parent-perceived sleep and breathing difficulties that significantly improved post-A/T. BASC T scores for externalizing and internalizing behaviors improved post-A/T, e.g., behavioral symptom index mean pre-A/T was 56.2 (95% confidence interval, 52.8 -59.6) compared with 50.9 (48.5-53.5) post-A/T. Some measures indicative of impulsivity and attentiveness obtained from the visual CPT before surgery, improved post-A/T, but no change was observed in any auditory CPT measures. Our data confirm improvements in subjective measures of sleep problems in children treated for SRBD and strengthen the notion of treating the disorder, not only related to the obvious clinical condition but also to the underlying sleep problems and adverse effects on daytime behavior and attention. (1), with snoring, difficulty breathing, apnea, and persistent mouth breathing that ranges from primary snoring, through upper airways resistance syndrome, to OSA. The most common treatment for children with adenotonsillar hypertrophy or recurrent tonsillitis is A/T. This has been shown to result in clinical improvement in the majority of cases. In severe cases involving OSA, failure to treat can be associated with serious morbidity such as failure to thrive and systemic hypertension, and pulmonary hypertension with or without cor pulmonale can develop (1).SRBD have been linked to daytime behavioral problems, predominantly those associated with hyperactivity, aggression, and inattention (2-4), and poorer performance on tests of memory and intelligence (5). At short-term follow-up after treatment, significant improvements in children's vigilance and behavior in areas of aggression, inattention, impulsivity and hyperactivity (6,7), and quality of life (8) have been reported. Also reported are short-term improvements in several cognitive factors such as perceptual closure, inference, organization, visual and auditory short-term memory, ability to solve problems and think analytically (9), and learning 1 y after treatment for a SRBD in poor academic achievers (10).The main physiologic characteristics during sleep for children with SRBD are intermittent hypoxemia associated with frequent apneas, hypopneas and sleep fragmentation due to frequent arousals, awakenings, and a red...

despite general agreement that altered reward sensitivity is involved in attention-deficit/hyperactivity disorder (adhd), a wide range of different alterations has been proposed. we cite work showing abnormal sensitivity to delay of reward, together with abnormal sensitivity to individual instances of reward. we argue that at the cellular level these behavioural characteristics might indicate that dopamine timing is off in children with adhd.

Our PSG findings show no strong link between ADHD and SDB although our findings could be limited by a small sample size. Findings from PSG studies in the literature argue both for and against an association between ADHD and SDB. Our results suggest medication is not a factor in the debate.

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