| Abstract: | In order to know whether seasonal variations affect mood and the length of the menstrual cycle in tropical young women, we have conducted a survey with 200 female students in Hanoi, Vietnam. We used the Vietnamese-translated Self-rating Depression Scale (SDS) for the measurements of their mood. Each of them was given a calendar (from September, 1999 to August, 2000) and was instructed to circle the first day of their menstruation, each month. The results showed that there existed a high prevalence of summer Seasonal Affective Disorder (SAD) and that the length of the menstrual cycle was affected by seasonal change. The average lengths of menstrual cycles were 30.7 ± 0.3 days (mean ± SEM) which is longer than in American young women. The higher occurrence of summer SAD seems to be related to the high ambient temperature during summer in the tropics, influencing their mood. |
