IntroductionThe disruption of biological rhythm (sleep, eating patterns, hormonal secretions, activities, and social life etc.) in individuals diagnosed with bipolar disorder makes it challenging to balance the mood of the patient and facilitates recurrence. Although social support, coping with stress, and medication adherence are known to affect prognosis, no study has been found to investigate the relationship between these factors and biological rhythm. AimThis descriptive and correlational design study investigated the relationship between perceived social support, coping styles and medication adherence, and biological rhythm in individuals diagnosed with bipolar disorder. MethodThis study was conducted with 111 patients receiving treatment in the outpatient clinics of the psychiatry department of two public hospitals in Ankara, Turkey. Biological Rhythm Interview of Assessment in Neuropsychiatry (BRIAN), Multidimensional Scale of Perceived Social Support (MSPSS), Coping Style Inventory (CSI), and Morisky Medication Adherence Scale (MMAS) were used for data collection. ResultsThe biological rhythm total and subscales scores were significantly and negatively related to perceived social support total, and subscales scores (p < 0.005). The biological rhythm total and most of its subscales scores were significantly and negatively related to medication adherence (p < 0.005). The biological rhythm total and domain scores were significantly and negatively related to seeking social support, self-confident, and optimistic subscales of CSI while significantly and positively related to helpless and submissive (p < 0.005). DiscussionIn this study, a positive relationship was found between increased perceived social support, effective coping with stress, and adherence to medication. This study highlights that these factors may be helpful for the regulation of biological rhythm.