This study compared screen time, circadian rhythm patterns, and sleep quality in adults diagnosed with attention-deficit/hyperactivity disorder (ADHD) and healthy controls, and examined the associations among these parameters. The sample included 100 adults with ADHD and 100 healthy controls. Participants were assessed using a sociodemographic data form, the Diagnostic Interview for ADHD in Adults (DIVA 2.0), the Structured Clinical Interview for DSM-5 Disorders (SCID-5-CV), the Adult ADHD Self-Report Scale (ASRS), the Biological Rhythm Interview of Assessment in Neuropsychiatry (BRIAN), the Pittsburgh Sleep Quality Index (PSQI), and the Screen Exposure Questionnaire. All instruments except the DIVA 2.0 were administered to controls. Adults with ADHD reported significantly longer total daily screen time than controls ( < 0.001) and exhibited higher ASRS, BRIAN, and PSQI scores (all < 0.001) In both groups, screen time was positively correlated with BRIAN and PSQI scores. Hierarchical regression analysis indicated that biological rhythm disruption (BRIAN scores) was a stronger predictor of poor sleep quality (PSQI scores) than ADHD symptom severity or screen time ( < 0.001)). Overall, adults with ADHD demonstrated greater screen exposure, more disrupted circadian rhythms, and poorer sleep quality compared to controls. Across the full sample, biological rhythm disruption emerged as the most robust predictor of impaired sleep, underscoring its potential clinical relevance for addressing sleep disturbances in adults with ADHD. p p p
