SEASONAL-VARIATIONS OF CURRENT SYMPTOMS IN A HEALTHY POPULATION

Among a large workplace population interviewed over a year, current sy mptoms were assessed using the Hopkins Symptom Checklist (HSCL). Varia tion in symptoms by date of assessment was observed among the 314 wome n but not the 1556 men. Among women, symptoms were greatest during lat e autumn and winter, and significant inverse correlations were found b etween available daylight at the time of assessment and standard sympt om dimensions of anxiety and somatisation, as well as an expanded mood scale more inclusive of depressive symptoms within the check-list. Th e amplitude of the seasonal effect was such that the prevalence of fem ale 'cases', as defined by HSCL criteria, was twice as high during win ter than during the rest of the year. The data are consistent with a r ole for light-dark exposure in eliciting or synchronising annual mood rhythms. The sex-by-season interactions may contribute to the sex diff erences in overall prevalence of depression.