The relation of chronotype with clinic and comorbidity in attention deficit hyperactivity disorder adolescents

Objectives: There is growing evidence to support the effect of circadian preferences on mental health. However, very little information exists on how chronotypes affect the ADHD clinic. This study aims to investigate the relation of chronotype with clinical symptoms and comorbidity in adolescents with ADHD. Material and Methods: The study sample consisted of 306 patients (189 males, 117 females) aged between 12 and 18 years who diagnosed with ADHD (ADHD-I: % 48,4; ADHD-C: % 51,6). Conner's Parent Rating Scale, Turgay DSM–IV Based Disruptive Behavior Disorders Screening and Rating Scale, Behavior Rating Inventory of Executive Function, Children's Chronotype Questionnaire, Self-Administered Rating Scale for Pubertal Development, Children's Depression Inventory, State-Trait Anxiety Inventory, and Stroop test were administered. Results: The most common chronotype was the evening (% 49,35) according to self-reports. Chronotypes did not differ between ADHD subtypes. Evening chronotype had significantly higher anxiety, depression, oppositional, social problems, psychosomatic symptoms than morning types. Evening chronotype group displayed more severe problems in all executive function measures than other two chronotypes. In males, intermediate chronotype and, in females, evening chronotype were more common. Increasing in chronotype scores was associated with shorter sleep time (for weekly and school days), longer daytime nap duration and screen time. Evening chronotype higher in patients with ODD comorbidity than patients without comorbid ODD. Multiple linear regression analysis showed that chronotype scores significantly linked to male gender, pubertal developmental scores, depression, and trait anxiety scores (by self-report) and, also screen time, mother's educational status, hyperactivity, psychosomatic problems, global executive and monitoring ability (by parental report). Conclusion: Although chronotypes did not differ between ADHD subtypes, our findings have shown that evening chronotype associated with increases in ADHD symptoms, anxiety and depression symptoms and, also executive function problems. Additionally, it was demonstrated that evening chronotype has shorter sleep time. Keywords: Attention Deficit Hyperactivity Disorder, Adolescent, Chronotype, Executive Functions