Objective: The goal of this study was to estimate the frequency of seasonal
variations in mood and behavior among Chinese medical students. Method: A
total of 1,358 medical students were surveyed with Chinese versions of the
Seasonal Pattern Assessment Questionnaire and the Beck Depression Inventory
in Jining, China. Results: The mean global seasonality score was 8.3 (SD=3
.6) out of a possible 24; 81.7% (N=1,110) of the subjects reported some tro
uble adapting to changing seasons. Summer difficulties were more common tha
n winter difficulties by a ratio of 3:2; estimated rates of summer seasonal
affective disorder and subsyndromal seasonal affective disorder were 4.4%
and 8.0%, respectively, compared with corresponding winter rates of 2.4% an
d 5.7%, Conclusions: These results suggest that seasonal variations in mood
and behavior are common in China. The predominance of summer difficulties
stands in contrast to that in most Western studies and is consistent with t
he only other published study performed in Asia.