Persistence and remission of depressive and generalized anxiety symptoms among adolescent mothers in Mwanza, Tanzania: a longitudinal observational study embedded within a non-pharmacological intervention cohort

Background There is paucity of literature on the persistence and remission rates of depressive and anxiety symptoms during pregnancy and to our knowledge, no studies have examined these trajectories among adolescent mothers. Moreover, associated psychosocial risk and protective factors remain largely underexplored. To begin to address these gaps, we used longitudinal data from a cohort of pregnant adolescents in Mwanza, Tanzania, who participated in a non-pharmacological intervention to examine the remission and persistence of depressive and generalized anxiety symptoms from pregnancy through to three months postpartum. Methods A total of 533 pregnant adolescents were enrolled during their second trimester using a convenience sampling approach from selected antenatal care clinics in Mwanza, Tanzania, between 5 August 2023 and 30 June 2024. Depressive symptoms were assessed using the Edinburgh Postnatal Depression Scale (EPDS) and generalized anxiety symptoms were assessed using the Generalized Anxiety Disorder–7 (GAD-7) scale. Assessments were conducted at four time points: second trimester (Time 1), third trimester (Time 2), four weeks postpartum (Time 3), and three months postpartum (Time 4). Participants who screened positive for depressive and/or anxiety symptoms at Time 1, the initial assessment were followed longitudinally to three months post-delivery. Results Approximately one-third of adolescent mothers who screened positive for depressive or anxiety symptoms at Time 1, continued to report symptoms in the third trimester. Symptom remission rates were high postpartum, with more than 97% of participants who screened positive for depressive and anxiety symptoms at Time 1 reporting remission at three months post-delivery. Conclusions Maternal depressive and anxiety symptoms in adolescent mothers were dynamic, showing moderate persistence during pregnancy and marked remission in the postpartum period. These findings support the importance of integrating routine mental health screening alongside sustained psychosocial interventions into antenatal and postnatal care to reduce the burden of perinatal mental disorders among adolescent mothers in low-resource settings.