Evidence of weekly cyclicity in mood and functional impairment in those with a bipolar disorder.

A key characteristic of bipolar disorder is fluctuation in mood symptoms and functional capacity, yet assessment of bipolar symptomatology often relies heavily on interval measurement that is unable to capture the full range of daily symptom variability and severity. The current study provides a detailed analysis of the variability in mood symptoms, functional impairment and medication compliance in a large sample of individuals newly diagnosed with bipolar disorder. Individuals diagnosed with bipolar disorder in the previous 12 months (n=192) rated their mood, functional impairment, medication compliance and symptom triggers daily over 10 consecutive weeks. High mood, low mood and functional impairment were found to vary on a weekly cycle, independently of medication compliance. Low mood and functional impairment were worse on weekdays, particularly Mondays and Tuesdays, whereas mood was most elevated on Saturdays. Work-related stressors were the most common symptom triggers on weekdays, whereas sleep-related problems and positive social events were the most common triggers on weekends. This study provides evidence that individuals newly diagnosed with bipolar disorder experience fluctuations in mood and functioning that vary according to a weekly cycle. This finding has implications for the assessment and treatment of patients, and for future research.