Résumé
Sleepiness and mind-wandering are frequently experienced by patients with attention-deficit/hyperactivity disorder (ADHD), without ever having been jointly explored. We aimed to investigate the co-occurrence of these two phenomena in ADHD adults. Drug-free ADHD adults (n = 25) and healthy controls (n = 28) underwent an online experience sampling of mind-wandering episodes and subjective sleepiness. Participants completed self-reported measures of mind-wandering and sleepiness in daily life. Higher trait of mind-wandering was observed in ADHD patients compared to controls. On the whole sample, self-reported mind-wandering propensity was strongly associated with the severity of inattentive, impulsive and hyperactive symptoms. During the probes, patients reported more frequent episodes of mind-wandering and mind-blanking, and higher sleepiness. Their mind-wandering episodes were less intentional and belonged less frequently to a structured succession of thoughts. In both groups, mind-wandering and mind-blanking were associated with higher sleepiness. On the SART, patients were less accurate than controls. We provide first initial evidence for higher propensity of mind-wandering and mind-blanking using experience sampling in patients with formal ADHD diagnosis. This propensity was associated with sleepiness without negatively impacting attention performances. Mind-wandering and sleepiness have common determinants potentially involved in ADHD pathophysiology. Correlates of mind-blanking in ADHD adults remain to be characterized.