Seasonal Mood and Behavioral Changes for Japanese Residents in the United Kingdom

Abstract

The aim of this study was to investigate seasonal changes in mood and behavior for Japanese residents in UK A questionnaire survey was conducted with Japanese residents in the UK (n = 100) who participated both a combination winter and summer research. First, a longitudinal study comparing two surveys—one in summer and another in winter—was carried out to determine how the level of seasonal changes influenced depression among Japanese living in the UK. Then, we examined seasonal changes in mood and behavior over a 12-month period based on the degree of seasonal dependence. Paired t-tests on Global Seasonality Score (GSS score) and the Center for Epidemiologic Studies Depression Scale (CES-D) scores by winter and summer demonstrated that each score had a significant seasonal difference; individual scores were higher in winter than in summer. We examined the difference between high seasonality group, medium seasonal group, and non-seasonal group, regarding to the winter CES-D and summer CES-D scores. The ANOVA revealed a significant difference on the winter score (Winter: F(2,97) = 4.62, p < .01, Summer: F(2,97) = 3.24, p < .05). Although we did not find any interaction between seasonal change and season, the main effect was significant for season. The results showed fluctuations in which mood, social activity, and sleep all declined during the winter and then improved during the summer. It indicated that depressive symptoms among Japanese living in the UK fluctuate due to seasonality; over a period of 12 months, their mood and behavior declined during winter and improved during summer. As described, Japanese living in the UK experience environmental changes due to seasonality. This suggests that the environmental factor called seasonal change can partly explain why Japanese living in the UK suffer from mental and physical disorders. Mental health measures specific to the local environment are necessary to support individuals to adapt to and live under an environment different from home country.