Unravelling symptom-specific polygenic effects on maternal mental health during the perinatal period and postpartum

This is the authors' abstract. We don't add key points for this paper.

While genetic factors are important influences on maternal mental health, few studies have used symptom-level analyses to examine how genetic liability is related to the experience of specific mental health problems in mothers. A symptom-level approach can account for disorder heterogeneity and delineate key associations between genetic liabilities and mental health. Three waves of data (30 weeks of gestation, 6 and 18 months postpartum) from the Norwegian Mother, Father and Child Cohort Study (MoBa) were used to assess item-level associations between genetic liabilities to depression, anxiety, neuroticism and positive affect, and maternal mental health phenotypes (i.e., symptoms of anxiety, depression, positive and negative affect) using a network analysis approach. Sample sizes ranged from 46,537 to 59,308 mothers. PGSs exhibited both phenotype-specific associations (e.g., depression PGS linked with hopelessness, anxiety PGS linked with worry) and cross-phenotype (e.g., depression PGS linked with nervousness, positive affect PGS inversely related to anxiety and depressive symptoms) relationships, with partial correlations ranging between r = −0.025 and r = 0.024. Some PGS-phenotype associations were consistent (e.g., depression PGS linked with feeling like screaming or banging on something across all waves) and others inconsistent (e.g., anxiety PGS linked with nervousness only at 6 months postpartum) across the perinatal and postpartum periods. Our findings highlight symptom-level associations between PGSs and maternal mental health, which may be obscured when global measures of mental health (e.g., overall scores) are used. Identifying symptom-specific PGS associations could advance current understanding of aetiological influences on maternal mental health. • Few studies have used symptom-level analyses to examine how genetic liability is related to mental health. • We applied network analysis in a sample of up to 59,308 mothers to examine how polygenic scores relate to maternal mental health phenotypes. • We identified both phenotype-specific and cross-phenotype associations and both consistency and inconsistency in associations across timepoints. • Our findings highlight symptom-level associations between polygenic scores and maternal mental health.