Research Summary

Breastfeeding During SSRI Treatment Not Linked to Lower IQ in Children, California Cohort Study Finds

Edited by:
Ashton L. Stahl

Key Highlights

  • In a cohort of 97 children prenatally exposed to selective serotonin reuptake inhibitors (SSRIs), IQ scores at 4-5 years did not differ between breastfed children exposed to SSRIs via breast milk and breastfed children without postnatal SSRI exposure.
  • Before full adjustment, breastfed children exposed to SSRIs postnatally had higher full-scale and performance IQ scores than non-breastfed children, but maternal mood–related factors explained these differences.
  • All exposure groups demonstrated mean IQ scores above standardized population averages, and subtest performance was broadly similar.

The study, published in JAMA Netw Open, evaluated whether exposure to selective serotonin reuptake inhibitors (SSRIs) through breast milk affects the cognitive performance of preschool-aged children already exposed to SSRIs in utero. Prior work has raised concerns about neurodevelopment after prenatal SSRI exposure, but the impact of postnatal exposure via breastfeeding has not been directly examined.

Researchers conducted a secondary analysis of the MotherToBaby California cohort, which enrolled pregnant women between 1989 and 2008. All included mothers were treated with SSRIs during pregnancy, and their children underwent standardized neurodevelopmental testing at 4 to 5 years of age between 1996 and 2012. Exposure, breastfeeding status, and covariates were captured through structured interviews and medical record review when available.

Children were grouped based on infant feeding and SSRI exposure: breastfed with SSRI exposure during breastfeeding (n = 22), breastfed without postnatal SSRI exposure (n = 37), and non-breastfed (n = 38). Breastfeeding was defined as at least 1 month of documented breastfeeding. The primary outcomes were full-scale IQ (FSIQ), verbal IQ (VIQ), and performance IQ (PIQ) measured with the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-R or WPPSI-III). Analyses used the assessment of covariance adjusted for child age at testing, sex, and prematurity, with stepwise sensitivity models including maternal alcohol use, other psychotropic medications, SSRI duration, and depressive symptoms.

Study Findings

Among the 97 children (53.6% female; mean age 4.9 years), mean FSIQ was 105.8, VIQ 103.9, and PIQ 107.0, corresponding to above-average performance. Adjusted mean FSIQ in children exposed to SSRIs via breastfeeding (109.4; 95% CI, 104.5-114.4) was similar to that of breastfed children without postnatal SSRI exposure (106.1; 95% CI, 102.1–110.1; P =.29). Adjusted VIQ and PIQ scores were likewise comparable between these 2 breastfed groups.

Compared with non-breastfed children, breastfed children exposed to SSRIs during breastfeeding initially showed higher adjusted FSIQ (109.4 vs 103.1; P =.046) and PIQ (112.3 vs 104.2; P =.03). However, these differences were no longer statistically significant after additional adjustment for factors related to maternal mood during pregnancy. VIQ scores did not differ meaningfully between any of the exposure groups.

On WPPSI subtests, adjusted mean scores across groups were generally within 2 points of the standardized mean of 10, with all groups performing about 1 standard deviation above the mean on the Picture Completion test. Small but statistically significant differences in 2 nonverbal subtests (Geometric Design and Mazes) favored children exposed to SSRIs during breastfeeding over non-breastfed children, though absolute differences were less than 2 points.

Maternal depressive symptoms during pregnancy, measured by the Center for Epidemiologic Studies Depression Scale, were modestly and negatively correlated with child FSIQ and VIQ (R = −0.26 for both; P =.02), while no significant correlation was observed with PIQ.

Clinical Implications

According to the study authors, these findings indicate that additional exposure to SSRIs via breast milk in children already exposed prenatally was not associated with reduced IQ scores at preschool age. The attenuation of IQ differences after adjustment for maternal mood-related factors underscores the importance of considering underlying maternal psychiatric illness when interpreting neurodevelopmental outcomes in SSRI-exposed children. The authors note that neurodevelopmental domains beyond IQ were not assessed in this analysis.

Expert Commentary

“These findings are in line with previous studies that have shown positive effects of breastfeeding on child IQ. Based on these results, as well as other studies in the field, we conclude that mothers in need of treatment with SSRIs post-partum may be encouraged to breastfeed without discontinuation of the treatment,” the researchers concluded.

Reference

Heinonen EW, Kao K, Mattson SN, et al. Cognitive outcomes of children exposed to selective serotonin reuptake inhibitors through breast milk. JAMA Netw Open. 2025;8(11):e2544989. doi:10.1001/jamanetworkopen.2025.44989