Disentangling symptom dimensions in obsessive–compulsive disorder through objective physical activity and sleep metrics

Introduction Obsessive–compulsive disorder (OCD) is a heterogeneous condition characterized by distinct symptom dimensions, as “Contamination”, “Responsibility for harm”, “Symmetry”, and “Unacceptable thoughts”. Although these dimensions have been associated with clinical features and treatment outcomes, their relationship with behavioral parameters such as physical activity and sleep remains insufficiently understood. Evidence suggests that physical activity and sleep quality may influence symptom severity and clinical course in psychiatric disorders; however, OCD-specific data are limited. This study aimed to investigate the associations between OCD symptom dimensions, physical activity, sleep quality, and overall clinical status in a clinical sample. Methods Fifteen patients diagnosed with OCD were included. Symptom severity was assessed using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), and clinical status was evaluated using the Clinical Global Impression (CGI) scale. Sleep quality was measured with the Pittsburgh Sleep Quality Index (PSQI). Physical activity was recorded over three consecutive days using the SenseWear Armband, providing step count, metabolic equivalent (MET), total energy expenditure, and activity duration.Patients were grouped according to dominant symptom dimensions, and physical activity parameters were compared across groups. Associations between clinical variables and physical activity were examined using Spearman correlation analyses, and multiple linear regression analyses were performed to evaluate predictive effects. In regression models, symptom dimensions were entered as continuous variables rather than categorical classifications. The study was approved by the Karadeniz Technical University Scientific Experiments Ethics Committee (Approval No: 2025-332). Results The most prevalent dominant symptom dimensions were Contamination (n=7, 46.7%) and Responsibility for harm (n=6, 40.0%). No statistically significant differences in physical activity parameters were observed across symptom dimensions (p>0.05).Trend-level findings indicated that individuals with lower illness severity exhibited higher physical activity, whereas those with greater severity showed reduced activity levels. Similarly, better treatment response was associated with higher activity levels across participants.Y-BOCS scores showed a negative association trend with physical activity, indicating that higher symptom severity was associated with lower activity levels. Sleep quality indicated a negative association trend with physical activity and a positive association trend with illness severity. These patterns were consistent across multiple activity parameters.In regression analyses, none of the examined clinical variables significantly predicted physical activity parameters (p>0.05). Discussion Although no statistically significant associations were identified, the observed trends suggest that physical activity and sleep quality may be meaningfully related to clinical status in OCD. Higher physical activity and better sleep quality were associated with lower symptom severity and more favorable clinical outcomes, supporting a potential modulatory role of these behavioral factors.The limited impact of symptom dimensions suggests that behavioral outcomes in OCD may not be determined solely by symptom content, but rather by broader processes such as mood, motivation, avoidance, and functional impairment. These findings highlight the importance of considering OCD beyond symptom-based classifications, incorporating behavioral and functional dimensions into its conceptualization.The small sample size represents an important limitation; however, the results provide preliminary evidence supporting the relevance of physical activity and sleep quality in OCD, warranting further investigation in larger and longitudinal studies.

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