Active and passive smoking and depression among Japanese workers.

Objective: To assess the relation of passive and active smoking to depressive symptoms in 1839 men and 931 women working in a suburb of Tokyo in 2002.

Method: Self-reported smoking history and exposure to passive smoking (no, occasional, or regular) at work and at home. Depressive symptoms according to the Center for Epidemiologic Studies Depression Scale, with a cut-off point of 16.

Results: Compared to never smokers unexposed to passive smoking, never smokers reporting regular and occasional exposure to passive smoking at work had increased depressive symptoms. The adjusted odds ratios (aORs) were 1.92 (95% confidence interval (CI) 1.14, 3.23) for regular exposure and 1.63 (95% CI 1.08, 2.47) for occasional exposure. Current smokers had significantly increased depressive symptoms (aOR ranging from 2.25 to 2.38) but former smokers had only marginal increases of depressive symptoms (aOR ranging from 1.43 to 1.55). Gender did not modify the effects of active/passive smoking on depressive symptoms.

Conclusion: Passive smoking at work and current smoking appear associated with higher levels of depressive symptoms.