A cross-sectional study of factors affecting seasonality in bipolar disorder

Background. Researchers have evinced interest in the effect of seasonal variations on mood and behavioural patterns in affective disorders. Objective. To study seasonality in bipolar disorder (BD) patients and also the factors affecting this seasonality. Method. Forty-nine patients with BD in euthymic phase were recruited and analysed using the Seasonal Pattern Assessment Questionnaire and Morningness-Eveningness Questionnaire. Results. Most of the patients were morning types but chronotype had no influence on seasonality. Age of patient and number of episodes were the most important factors affecting seasonality in BD. Conclusion. Seasonality and its influencing factors must be considered while managing bipolar disorder.