Factors associated with maternal depressive symptoms up to 25 years after childbirth: A longitudinal prospective cohort study

Depression is one of the most common mental disorders among women and previous depression increases the risk for new episodes. Little is known about which factors are associated with maintained or recurrent depression in women, and studies with longer follow-up time, 20 years or more, are scarce. Thus, the aim of the study was to identify factors associated with repeated self-reports of depressive symptoms. The hypothesis was that factors such as young age at childbirth, divorce, unemployment, low social support, prior depression, or experience of stressful life events would increase the risk of repeatedly reporting depressive symptoms. The South East Sweden Birth Cohort study is a longitudinal, prospective cohort study. Out of the 1694 mothers enrolled at baseline, 649 participated in the 25-year follow-up. A total of 450 mothers participated in all three follow-ups. The mothers reported symptoms of depression using validated instruments at 3 months (Edinburgh Postnatal Depression Scale), 12 years (Hopkins Symptom Checklist 25 items), and 25 years postchildbirth (Patient Health Questionnaire). Logistic regression was performed to evaluate the odds ratios of having depressive symptoms, whereas multinomial logistic regression was used to evaluate independent factors' association with the number of episodes with depressive symptoms. High life stress around pregnancy and childbirth and earlier depressive symptoms were associated with depressive symptoms at the 25-year follow-up. Similarly, high life stress around pregnancy and childbirth and the experience of divorce were associated with repeated self-reports of depressive symptoms. Stressful life events are important predictors of depressive symptoms and repeated episodes of depressive symptoms from the postnatal period until 25 years later. Moreover, previous depressive symptoms increase the risk for subsequent episodes. The results further stress the importance of identifying mothers experiencing depressive symptoms postpartum to enable treatment and early intervention.