Abstract

Background: Perinatal depression carries adverse effects on maternal health and child development, but genetic underpinnings remain unclear. We investigated the polygenic risk of perinatal depressive symptoms.

Methods: About 742 women from the prospective Prediction and Prevention of Pre-eclampsia and Intrauterine Growth Restriction cohort were genotyped and completed the Center for Epidemiologic Studies Depression scale 14 times during the prenatal period and twice up to 12 months postpartum. Polygenic risk scores for major depressive disorder, bipolar disorder, schizophrenia, and cross-disorder were calculated using multiple p-value thresholds.

Results: Polygenic risk scores for major depressive disorder, schizophrenia, and cross-disorder, but not bipolar disorder, were associated with higher prenatal and postpartum depressive symptoms (0.8%–1% increase per one standard deviation increase in polygenic risk scores). Prenatal depressive symptoms accounted for and mediated the associations between the polygenic risk scores and postpartum depressive symptoms (effect size proportions-mediated: 52.2%–88.0%). Further, the polygenic risk scores were associated with 1.24–1.45-fold odds to belong to the group displaying consistently high compared with consistently low depressive symptoms through out the prenatal and postpartum periods.

Conclusions: Polygenic risk scores for major depressive disorder, schizophrenia, and cross-disorder in non-perinatal populations generalize to perinatal depressive symptoms and may afford to identify women for timely preventive interventions.