RESUMO
BACKGROUND: In contrast with recurrent unipolar depression, relatively little is known about the seasonality of depressive episodes in bipolar affective disorder (BAD). METHOD: We compared responses on the Seasonal Pattern Assessment Questionnaire (SPAQ) between a cohort of 183 patients with BAD and a large sample of patients in primary care (N=4746). Comparisons were adjusted for age and gender. RESULTS: 27% of the BAD patients fulfilled SPAQ criteria for Seasonal Affective Disorder (SAD. This gave an adjusted odds ratio of 3.73 (95% confidence intervals 2.64 to 5.27) in comparison with the rate among the primary care samples. Global seasonality scores were significantly higher among BAD patients (adjusted mean difference 1.73, 95% CI 0.97 to 2.49, p<0.001). LIMITATIONS: The SPAQ was originally designed as a screening instrument rather than as a case-finding instrument. CONCLUSIONS: Vigilance for seasonal symptom recurrence in BAD may be important with regard to management and relapse prevention.
