Prenatal serotonin reuptake inhibitor antidepressant exposure, SLC6A4 genetic variations, and cortisol activity in 6-year-old children of depressed mothers: A cohort study.

Prenatal exposure to maternal depression and serotonin reuptake inhibitor (SRI) antidepressants both affect the development of the hypothalamic-pituitary-adrenal (HPA) system, possibly via the neurotransmitter serotonin (5HT). In a community cohort, we investigated the impact of two factors that shape prenatal 5HT signaling (prenatal SRI [pSRI] exposure and child SLC6A4 genotype) on HPA activity at age 6 years. Generalized estimating equation (GEE) models were used to study associations between cortisol reactivity, pSRI exposure, and child SLC6A4 genotype, controlling for maternal depression, child age, and sex (48 pSRI exposed, 74 nonexposed). Salivary cortisol levels were obtained at five time points during a laboratory stress challenge: arrival at the laboratory, following two sequential developmental assessments, and then 20 and 40 min following the onset of a stress-inducing cognitive/social task. Cortisol decreased from arrival across both developmental assessments, and then increased across both time points following the stress challenge in both groups. pSRI-exposed children had lower cortisol levels across all time points. In a separate GEE model, we observed a lower cortisol stress response among children with LG /S alleles compared with children with La/La alleles, and this was particularly evident among children of mothers reporting greater third trimester depressed mood. Our findings suggest that pSRI exposure and a genetic factor associated with modulating 5HT signaling shaped HPA reactivity to a laboratory stress challenge at school age.

Children's stress regulation mediates the association between prenatal maternal mood and child executive functions for boys, but not girls.

Prenatal exposure to maternal mood disturbances shapes children's cognitive development reflected in the critical construct of executive functions (EFs). Little is known, however, about underlying mechanisms. By examining cortisol responses in both everyday and lab challenge settings, we tested whether the child/offspring hypothalamic-pituitary-adrenal axis mediates effects of prenatal maternal mood on child EFs at age 6. In 107 Canadian children born to women with a wide range of anxious and depressive symptoms during pregnancy, we found that in boys but not girls, depressed and/or anxious prenatal maternal mood is associated with heightened diurnal cortisol levels in everyday settings, as well as heightened cortisol reactivity to a lab challenge and that this heightened reactivity was associated with poorer EFs. Among boys we also observed that cortisol reactivity but not diurnal cortisol mediated the association between depressed and/or anxious prenatal maternal mood and EFs. Depressed and/or anxious prenatal maternal mood was related to child EFs for both girls and boys. To our knowledge, this is the first study to demonstrate a mediating role for child stress regulation in the association between prenatal maternal stress-related mood disturbances and child EFs, providing evidence of a mechanism contributing to fetal programming of cognition.

Sculpting infant soothability: the role of prenatal SSRI antidepressant exposure and neonatal SLC6A4 methylation status.

The role of prenatal Selective Serotonin Reuptake Inhibitor (SSRI) exposure and SLC6A4 promoter methylation status in shaping soothability at 3 and 6 months of age, for infants exposed to antidepressant medication prenatally (n = 46) and those not exposed (n = 69) was investigated. SSRI exposure status and duration of exposure (number of days) were examined along with neonatal methylation status at mean CpG 9,10 and via factor analysis across 10 CpG sites yielding PC1 (CpGs sites: 3,4,5,7) and PC2 (CpG 1,8). Analyses revealed interactions for methylation markers and SSRI exposure variables. A significant interaction between SSRI exposure and mean SLC6A4 methylation at CpG 9,10 and separately for PC1 emerged, controlling for multiple birth/medical and background covariates (e.g., Apgar scores, maternal education). Increased neonatal methylation status was associated with increased soothability changes from 3 to 6 months among infants prenatally exposed to SSRIs.