The Effects of Stimulant Medications on the Sleepiness Curve of Young Men with Attention-Deficit Hyperactivity Disorder (ADHD)

Background The present study aimed at investigating the effects of sleep deprivation and stimulant medication (methylphenidate and amphetamine) on subjective sleepiness in young adults with ADHD, compared to individuals without ADHD. Methods Fifty-nine young men (age 18–35) of whom 39 were diagnosed with ADHD combined type (ADHD-C) and 20 without ADHD. The participants’ sleep was monitored for 5 days via actigraphy. Subsequently, the participants were kept continuously awake in a controlled environment for 25 hours (8amtill 9am the next day). Among the ADHD group, 17 participants were medicated with their regular doses of methylphenidate (n = 13) or amphetamine (n = 4) at the start of the experiment (08:00 AM) and again at midnight (00:00), while 22 were unmedicated throughout the study. 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 Unmedicated ADHD participants reported significantly higher sleepiness throughout the protocol, especially during nighttime and early morning hours. At the end of the 25-hour wakefulness period, their KSS scores were significantly higher than both the control and medicated ADHD groups. No significant difference was found between the medicated ADHD group and controls. Additionally, 88.2% of unmedicated ADHD participants scored above 7 on the KSS (indicating extreme sleepiness), compared to 55% in controls and 36.9% in the medicated ADHD group. Conclusions Young adults with ADHD exhibit heightened vulnerability to sleep deprivation, reflected in elevated subjective sleepiness. Stimulant medications effectively attenuate sleepiness in ADHD participants, aligning their alertness levels with those of neurotypical controls. These findings support models of ADHD involving arousal dysregulation and highlight the dual therapeutic role of stimulants in managing both attentional deficits and sleep-related impairments