Factors associated with seasonal affective disorder: Findings from the bipolar disorder course and outcome study from India (BiD-CoIN study)

Background: There is a lack of information on the long-term course and outcomes of bipolar disorder (BD) patients with seasonal affective disorder (SAD).

Aim: To compare the demographic and clinical profile of BD patients with and without SAD.

Methodology: Data from 773 BD patients with an illness duration of at least 10 years were collected from 14 tertiary care centers. SAD was defined according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria. Participants with and without SAD were compared for demographic and clinical features.

Results: The prevalence of SAD was 9.44 %. BD patients with SAD spent more time in episodes (p < 0.001), had a higher number of lifetime episodes (p < 0.001), and more episodes per year of illness in the lifetime. They also spent more time in depressive episodes (p < 0.001), had higher depressive (p < 0.001) and manic (p = 0.01) affective morbidity indices, shorter durations of current remission (p < 0.001), higher levels of residual depressive and manic symptoms, higher levels of disability, and received more medications (p < 0.001). Patients with SAD were also more likely to have BD-II (p = 0.01), rapid cycling (p < 0.001), a first-lifetime episode of depressive polarity (p = 0.01), a history of breakthrough episodes (p < 0.001), self-discontinuation of pharmacoprophylaxis, and relapses due to poor medication adherence. They were more often receiving lithium, antipsychotics, and antidepressants. However, a lower proportion of those with SAD had been hospitalized, received electroconvulsive therapy, or were receiving valproate.

Conclusion: Patients with SAD, in general, have more severe BD, and differ from those without SAD on many clinical parameters.