Seasonality in a general population sample in Japan

1995 Fiscal Year Final Research Report Summary

• Project/Area Number: 06670981
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: Psychiatric science
• Research Institution: Toho University, Faculty of Science
• Principal Investigator: OGURI Mitsugu Toho University, Faculty of Science, Professor, 理学部, 教授 (60120250)
• Project Period (FY): 1994 – 1995
• Keywords: seasonal affective disorder / SAD

Research Abstract

We have conducted a population survey of seasonality in 6 representative cities in Japan ; Sapporo, Akita, Choshi, Narashino, Tottori and Kagoshima. Japanese version of the seasonal pattern assessment questionnaire (SPAQ) which asks for judgments of symptom severity and temporal pattern in seasonal affective disorder was made with reference to SPAQ by Rosenthal et al (1987). The quesionnaires were diliver to 1800 subjects (M/F=1/1) : 600 high-school students aged in 16-18 years and 1200 of their parents. They rated the degree of seasonal change in sleep length, social activity, mood, weitht, appetite and energy ; identified the months of the year (if any) in which they had changes in above items and rated the degree to which seasonal changes presented a personal problem in their lives.
The analysis was made for 951 subjects of parents, aged 44.8ア3.9 years. The tendency of an extension of sleep length and of an increase of weight in subjects in Akita and Sapporo (a northern snow area) was shown compared with it in the other areas in winter. Significant differences were made in subjects in the areas of Japan on seasonal variations of sleep length, of wight, and of social activity.
Two groups were divided with the criteria of Rosental et al, high seasonality group (HSG) over/equal 8 point of global seasonal score and low seasonality group (LSG) under 8 points of it. The ratios of HSG in Akita and Sapporo, 16.5% and 14.7%, were higher than that in the other southern areas, 11.4% in the mean. The sexual difference was not shown between two groups. This HGS was feeling worse in cold and humid weather, in gray cloudy and foggy days and in short days. These results mentioned above that the seasonality in northern snow areas appeared to be higher than that in southern sunny areas and there is sub-syndromal group of esasonal affective disorder in Japan.