The association between biological rhythm and psychosocial functionality in patients diagnosed with bipolar disorder 1 and in healthy first degree relatives

Aim: Circadian rhythm dysregulation is one of the important mechanisms playing a role in the pathophysiology of bipolar disorder (BD). This study aims to examine the relationship between deterioration in circadian rhythm and psychosocial functionality among patients with BD, healthy first-degree relatives, and a control group. Material and Methods: We planned a cross-sectional study consisting of 64 BD patients, 64 healthy first-degree relatives, and 64 healthy controls. We used the Biological Rhythms Interview of Assessment in Neuropsychiatry to assess disruption in circadian rhythm, the Morningness-Eveningness questionnaire to determine chronotypes, and the Functioning Assessment Short Test to assess functionality. Results: In our study, it was found that the circadian rhythms of BD patients were more disrupted than those of the control group, while the BD group was found to exhibit higher rates of morningness and eveningness than patient relatives and healthy controls. It was determined that the circadian rhythms of BD patients with evening chronotype were more disrupted, whereas an association was noted between dysregulation circadian rhythm and deteriorated functionality in the patient group. Discussion: In light of the obtained data, it can be suggested that circadian rhythm disorder in BD patients may be an independent predictor of low psychosocial functioning. Our study supports that therapeutic interventions targeting circadian rhythm stability play an important role in the acute and long-term management of BD.