Abstract
This study investigates the longitudinal association between living arrangements and psychiatrists' diagnosis of depression in the general population. In 1990, 1254 Japanese men and women aged 40-59 years were enroled and completed questionnaires on the living arrangement in the Japan Public Health Center-based Prospective Study (JPHC Study) and participated in a mental health screening (2014-2015). The study diagnosed a major depressive disorder (MDD) assessed by well-trained certified psychiatrists through medical examinations. During the follow-up, a total of 105 participants (36 men and 69 women) aged 64-84 years were diagnosed with MDD by psychiatrists. Living with a child (ren) was associated with a reduced risk of MDD for men but not for women; the respective multivariable ORs (95% CIs) were 0.42 (0.19-0.96) and 0.59 (0.32-1.09). These associations remained unchanged after adjusting for living with spouse and parent(s). In conclusion, living with a child (ren) was associated with a reduced risk of MDD in men, suggesting the role of a child (ren) in the prevention of MDD.