The Sleepiness Curve of Young Men With and Without Attention-Deficit Hyperactivity Disorder (ADHD)

Objectives: The present study aimed at comparing the sleepiness curve of young men with attention-deficit hyperactivity disorder (ADHD) to that of young men without ADHD before, during, and after a night of sleep deprivation. Participants: Thirty young men (age 18-30) of whom 14 were diagnosed with ADHD combined type (ADHD-C) and 16 without ADHD. Methods: The participants' sleep was monitored for 5 days via actigraphy. Subsequently, the participants were kept continuously awake in a controlled environment for 25 hr (8:00 a.m.-9:00 a.m.). The sleepiness of the participants was assessed every hour by the Karolinska Sleepiness Scale (KSS) in order to obtain the sleepiness curve of both study groups. Results: Actigraphy data demonstrated that the two groups did not differ in their total sleep time, sleep onset latency, or sleep efficiency during the 5 nights preceding the experimental session. However, during the experimental session, the ADHD group demonstrated higher sleepiness scores, particularly following midnight and on the morning following the night of sleep deprivation. Moreover, on the morning following sleep deprivation the proportion of participants reporting extreme levels of sleepiness (KSS > 7) was significantly higher in the ADHD group than in the control group. Conclusions: Young men with ADHD suffer from sleepiness more than their counterparts from the general population, and are particularly vulnerable to the effects of sleep deprivation on sleepiness. As excessive daytime sleepiness negatively affects cognition and increases the risk for motor vehicle crash and other accidents, these findings may have important clinical implications.