The impact of subjective and objective social status on psychological distress among men and women in Japan

From around 1990s, social disparity issues and their effects on mental health have been gaining increasing attention in Japanese society. Findings from previous studies on socioeconomic status (SES) and mental health in Japan are inconsistent. Subjective Social Status (SSS) has been proposed and tested as a stronger predictor of mental health than measures such as education, income and occupation in the UK and US, but this has not been tested enough in countries with a different social and cultural background such as Japan. In the present study, a cross-sectional questionnaire survey was conducted in 2006 among a nationally representative community-based random sample of residents in Japan aged 20–74 years. A total of 1237 participants completed the questionnaire, with the overall response rate of 61.9%. After excluding 42 respondents, data from 1195 respondents (574 men and 621 women) were analyzed. SSS, household income, and education level of respondents were measured using single-item questions. Those with a K6 score of 5 or greater were defined as having psychological distress. A multiple logistic regression model was used to examine the effects of SSS, household income, and education on psychological distress. Among men, the prevalence of psychological distress, after adjusting for age and marital status, differed significantly across groups classified based on SSS, household income, and education. Among women, only SSS was significantly associated with psychological distress after adjusting for age and marital status. However, when all three variables were simultaneously entered into the model, SSS and household income were significantly associated with psychological distress, with the low SSS group having a higher odds ratio of psychological distress. In summary, SSS seems to be a stronger predictor of psychological distress among both men and women in the Japanese community than traditional measures of SES.