Chronotype preference and circadian markers in children and adolescents with obsessive–compulsive disorder: A case–control study

Background Circadian rhythm disturbances have been implicated in several psychiatric disorders; however, circadian characteristics in pediatric obsessive–compulsive disorder (OCD) remain insufficiently investigated. Chronotype, reflecting individual differences in circadian timing, has been associated with both psychopathology and symptom severity in various psychiatric conditions. This study aimed to examine chronotype distribution in children and adolescents with OCD and to investigate the relationship between chronotype and OCD symptom severity using both psychometric assessments and biological circadian markers. Methods This cross-sectional clinical study included 29 children and adolescents diagnosed with OCD and 30 age- and sex-matched healthy controls. Psychiatric diagnoses were confirmed using the Kiddie Schedule for Affective Disorders and Schizophrenia – Present and Lifetime Version (K-SADS-PL). Chronotype was assessed using the Children's Chronotype Questionnaire (CCQ). OCD symptom severity was evaluated with the Children's Yale–Brown Obsessive–Compulsive Scale (CY-BOCS). Depression and anxiety symptoms were assessed using the Children's Depression Inventory (CDI) and the Screen for Child Anxiety Related Emotional Disorders (SCARED). Sleep disturbances were evaluated using the Sleep Disturbance Scale for Children (SDSC). Morning salivary melatonin and cortisol levels were measured as endogenous circadian markers. Results Evening chronotype was more frequent in the OCD group compared with healthy controls (p < 0.05). Within the OCD group, participants with evening chronotype showed significantly lower CY-BOCS scores compared with non-evening chronotypes (p < 0.05). Melatonin levels were significantly higher in the evening chronotype subgroup (p < 0.05), whereas cortisol levels did not differ significantly between chronotype groups (p > 0.05). Conclusions Children and adolescents with OCD appear more likely to exhibit evening chronotype characteristics. The association between chronotype and OCD severity suggests that circadian profiles may play a role in the clinical presentation of pediatric OCD. Considering chronotype characteristics during clinical assessment may contribute to a better understanding of circadian influences on OCD.