The longitudinal course of depressive symptoms during the perinatal period: A systematic review

Background: Perinatal Depression (PND) is one of the most common complications (10-20 %) during the peri-natal period and its clinical course and phenotypes are still an area of research. It is becoming increasingly clear that pregnant women and mothers with depression are not a homogeneous clinical group.Methods: A systematic literature search in 4 databases revealed 359 studies, 33 relevant studies met the inclusion criteria. We only included studies with at least three assessment points in total.Results: Two to six trajectory classes were identified. A three trajectories solution was most observed. All the included studies reported a low symptom trajectory but ranged from 6.5 % to 92 %. The high-symptom group was in most of the studies the smallest subgroup (1.1 % -14.6 %). Most of the studies described episodic tra-jectories of depressive symptoms during the peripartum. The most common risk factor associated with a high-symptom trajectory of depressive symptoms in our study was a history of depression. Important socio-demographic predictors were: young age, ethnicity, low maternal education, low income, single relationship status or relationship problems, unplanned or unintended pregnancy and experiencing high stress levels. Limitations: The methodology and the observed PND trajectories of the included studies differed, which makes generalizability difficult in this review.Conclusions: PND is a frequent but heterogeneous disorder. Globally, four major groups could be distinguished: low, medium, high and episodic trajectories. There is a need for consensus regarding which assessment in-struments to use, validated cutoff scores and similar time points of assessment.