Summer and winter patterns of seasonality in Chinese college students: a replication

The goal of this study is to replicate an earlier epidemiological finding of seasonal changes in mood and behavior among Chinese medical students using an independent study population. Three hundred nineteen college students were surveyed with a Chinese version of the Seasonal Pattern Assessment Questionnaire (SPAQ) and the Beck Depression Inventory (BDI) in Jining, China, during March of 1996. The frequency of seasonal patterns and prevalence rates of seasonal affective disorder (SAD) were estimated and compared with data from the medical student survey conducted in the same city. The mean Global Seasonality Score (GSS) of this college student sample was 9.9 +/- 4.9; 84% of the subjects reported some problems with the changing seasons. Summer difficulties were more prevalent than winter difficulties by a ratio of 1.9 to 1 (38.9% v 20.1%). The estimated rates of summer SAD and subsyndromal-SAD (s-SAD) were 7.5% and 11.9%, respectively, as compared with the corresponding winter figures of 5.6% and 6.3%. In addition, the prevalence estimates of winter pattern or winter SADs were higher in males than in females, but the corresponding summer figures showed no gender difference. Compared with the data from the medical student survey, this college student sample had a higher GSS (P < .01) but comparable summer to winter and female to male ratios for the prevalence of SADs (P > .05). These results replicate our previous findings that seasonal problems are common in China, but the predominant problems are summer difficulties rather than winter difficulties, and there is no female preponderance in the prevalence estimates of such problems. Both findings stand in contrast to most Western studies but are consistent with the only other published study performed in the Orient.