Effect of Affective Temperaments Assessed by the TEMPS-A on the Relationship between Work-Related Stressors and Depressive Symptoms among Workers in Their Twenties to Forties in Japan

Relatively recently in Japan, immature-type depression, frequently classified in the bipolar II spectrum, has increased among workers in their twenties to forties. This study explored whether affective temperaments moderate the relationship between work-related stressors and depressive symptoms among this age group. In July 2004, self-administered questionnaires were distributed to all employees of a Japanese company. Eight hundred seventy-four employees (63%) returned the questionnaires, with 728 completed. Questionnaires included the 12-item General Health Questionnaire for assessing depressive symptoms, the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego-Autoquestionnaire version for assessing affective temperaments, the Effort-Reward Imbalance Questionnaire to assess work-related stressors and overcommitment, and questions regarding individual attributes and employment characteristics. Multivariate logistic regression analysis showed that affective temperaments moderated the relationship between work-related stressors and depressive symptoms. Effort (OR = 1.078), which represents job demands and/or obligations imposed on employees, and the upper tertile of overcommitment (OR = 1.589), which represents hyperadaptation to the workplace, were risk factors for depressive symptoms. Additionally, the results for cyclothymic (OR = 11.404) and anxious temperaments (OR = 1.589) suggested that depressive symptoms among this age group may be related to immature-type depression.