A preliminary analysis of large muscle group movements in adults with attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder diagnosed in children, but often persists into adulthood. Sleep disturbances frequently manifest as comorbid conditions in ADHD, leading to increased behavioral and emotional impairments. We aimed to investigate restless sleep, characterized by increased large muscle group movements (LMMs), and their role in sleep architecture among adults diagnosed with ADHD in compared to healthy controls.

A total of 21 adults with ADHD and 25 healthy controls were included. Full-night polysomnographic recordings of all participants were scored for sleep, sleep-related events and for LMMs.

Total LMM index did not differ between groups, while LMM indices during NREM sleep were consistently lower in the ADHD group (p < 0.008). Age was negatively correlated with LMM associated with arousal (t = -0.434; p = 0.049) and wakefulness (t = -0.446; p = 0.043) in NREM sleep. Sleep efficiency showed a negative correlation with LMM associated with wakefulness (t = -0.442; p = 0.045) and total LMM (t = -0.437; p = 0.048) in NREM sleep. Wakefulness after sleep onset was positively correlated with LMM associated with wakefulness in NREM sleep (t = 0.464; p = 0.034). Serum ferritin levels were significantly lower in ADHD patients (p = 0.004), and inversely correlated with LMM associated with arousal and wakefulness in NREM sleep.

Our study showed that, although ADHD patients exhibited lower LMM indices, particularly in NREM sleep, LMMs are significantly correlated with markers of sleep fragmentation (increased WASO and reduced sleep efficiency). Our findings also showed that low ferritin levels are correlated with poor sleep quality, especially when motor restlessness is suspected in patients with ADHD.