Association between depression among male workers and sleeping problems in Japan

Introduction: In Japan, suicide remains major cause of death and 30,000+ people commit suicide annually for consecutive 12 years from 1998. Workers account for more than 30 % of such cases and most of them are men. Depression often causes suicide and screening for sleeping complaints as a possible cause of depression is attracting attention from those who work in suicide prevention. We intended to clarify the association between sleeping problems and depression in working men. Methods: Participants were male workers aged 20-64 (average age: 37.3, SD ±11.2) who underwent periodic physical check-up. Questionnaire items included sleeping conditions, lifestyles, perceived stress and depression (scored 10+ using Japanese version k6). We employed a series of logistic regression analyses to investigate factors associated with depression. Results: Those who considered depressed were 63 men (11.1%). Items significantly associated with depression were perceived stress (OR:9.52), bad or depressed mood for more than 2 weeks (OR:4.34), sleeping problems (combined score of difficulty initiating sleep, difficulty maintaining sleep, difficulty maintaining sleep, early morning awakening, poor quality of sleep, and restless sleep) (OR: 3.06), irregular eating pattern (eating meals less than 3 times a day)(OR:2.89), and physical activity (3+ times a week) (OR: 0.12). Conclusion and discussion: Among male workers, factors associated with depression are perceived stress, sleeping problems, irregular eating pattern, and less physical activity. It is necessary to assess sleeping conditions among workers for early detection of depression to prevent suicide among them.