Association between age at menopause and depressive symptoms among postmenopausal women with depressive symptoms at baseline: results from SHARE and ELSA.

BACKGROUND: Evidence on the relationship between age at menopause and depressive symptoms remains limited, particularly among postmenopausal women with depressive symptoms at baseline. This study examined the association between age at menopause and depressive symptom levels over follow-up, including nonlinear and interaction effects. METHODS: We included 2959 postmenopausal women aged ≥50 years with baseline depressive symptom scores at or above cohort-specific cut-offs from ELSA (waves 4-9) and SHARE (waves 4-8). Age at menopause was categorized as <45, 45-55, or ≥55 years and also modeled continuously. Repeated CES-D (ELSA) and EURO-D (SHARE) scores during follow-up were analyzed using multivariable linear mixed-effects models. Restricted cubic splines assessed nonlinearity, interaction tests assessed effect modification, and multiple imputation addressed missing covariate data. RESULTS: Participants with early menopause had higher depressive symptom scores than those with menopause at 45-55 years in SHARE (β: 0.170; 95% CI: 0.001, 0.340) and ELSA (β: 0.379; 95% CI: 0.043, 0.716). Depressive symptom scores decreased with increasing age at menopause in SHARE (p=0.009) and ELSA (p=0.001). When modeled continuously, a one-year increase in menopausal age was associated with lower depressive symptom scores in SHARE (β: -0.013; 95% CI: -0.025, -0.001) and ELSA (β: -0.035; 95% CI: -0.059, -0.011). No evidence of nonlinearity or interaction was observed. CONCLUSIONS: Age at menopause may help identify postmenopausal women at higher risk of persistent depressive symptoms.