SEASONAL-VARIATION OF DEPRESSIVE SYMPTOMS IN ANTARCTICA

Symptom characteristics and risk factors for seasonal variation in dep ressive symptoms were prospectively examined in 119 men and women who overwintered in Antarctica. Over a 12-month period, this cohort report ed significant increases in their global depressive symptom scores as well as several individual symptoms associated with winter depression. Summer depression and marital status were significant independent pre dictors of winter depression. Factor analyses of summer and winter sym ptoms revealed a set of symptoms traditionally associated with the win ter-over experience in a distinct factor not found in summer. These re sults indicate that even asymptomatic, clinically normal populations e xperience seasonal variation in mood in high-latitude environments. Ho wever, this seasonal variation may be the result of social isolation d uring the winter months rather than the prolonged absence of sunlight.