Methylphenidate and Sleep in Adhd Introduction Actigraphs Are Small Devices, Usually Worn around the Wrist, That Detect and Store Move- Ment for Later Analysis of Levels of Activity,

ACTIGRAPHS ARE SMALL DEVICES, USUALLY WORN AROUND THE WRIST, THAT DETECT AND STORE MOVEMENT FOR LATER ANALYSIS OF LEVELS OF ACTIVITY, sleep and wake parameters, and circadian rhythm parameters.1 These measurement goals make actigraphy a useful tool for objectively studying attention deficit hyperactivity disorder (ADHD), since this disorder is by definition associated with hyperactivity and with sleep problems.2 Actigraphy has indeed been utilized in studying children with ADHD, but it has rarely been employed in adults with the disorder. We therefore conducted an extensive actigraphy study of daytime and nighttime activity, sleep/wake parameters, and circadian rhythms in adults carefully diagnosed with ADHD; we also collected data to measure the effects of stimulant medication. We gathered these data to provide tentative answers to the 4 research questions described below. 1) Are adults with ADHD more active (as measured by actigraphs) during the day and/or during the night than normal controls? Children with ADHD show higher levels of daytime activity than normal controls.3 We know of only one study that used daytime actigraphy in an adult population suspected of childhood ADHD. The patient group in this study could be distinguished from normal controls by higher activity counts from the actigraphs.4 However, the patient group in this study was primarily classified as “Antisocial Violent Offenders,” thus our study is the first to explore daytime activity in adult participants with a primary diagnosis of ADHD. With respect to nighttime activity, Cohen-Zion and Ancoli-Israel discussed 4 studies that utilized actigraphs in a child ADHD sample and they reported that the evidence was inconclusive, although most studies reported more nighttime activity and increased nighttime variability in activity levels.5 Two studies have used actigraphy to evaluate nocturnal activity in an adult ADHD population; in one study the ADHD group showed higher mean activity levels than normal controls,6 whereas the other study reported no difference.7 Both studies reported a higher movement index (percentage of epochs with an activity count > 0) during the night. 2) Are there differences in actigraphic sleep parameters between adults with and without ADHD? Problems with sleep are frequently reported in children with ADHD.2 In particular, parental reports of sleep problems in children with the disorder are highly prevalent, although results of more objective measurements of sleep (e.g., polysomnography) are equivocal; there does not seem to be one specific disturbance of sleep architecture relatHyperactive Night and Day? Actigraphy Studies in Adult ADHD: a Baseline Comparison and the Effect of Methylphenidate