Metabolomic signatures of SSRI exposure during neural differentiation and correlation of lysophosphatidylcholines with early symptoms of neurodevelopmental disorders

BACKGROUND: Selective serotonin reuptake inhibitors (SSRIs) are often prescribed during pregnancy. Epidemiological studies examining in-utero SSRI exposure and neurodevelopmental outcomes such as autism and ADHD have produced mixed results, in part due to challenges in accounting for underlying maternal mental health conditions and other confounding factors. The molecular pathways through which SSRIs may affect early neurodevelopment remain poorly understood. METHODS: We exposed neuroepithelial stem cells derived from four human induced pluripotent stem cell (iPSC) lines to fluoxetine, citalopram, sertraline, and paroxetine. We then assessed cellular viability, reactive oxygen species (ROS) levels, mitochondrial function using adenosine triphosphate (ATP) assays, and performed high-throughput metabolomics at two timepoints: proliferation and neural differentiation stages. The key metabolic findings were validated in the in-vitro model and in a complementary population-based cohort, the Barwon Infant Study, consisting of 1074 mother-child pairs with analysed cord-blood metabolomes. FINDINGS: Sertraline and paroxetine significantly decreased ROS and ATP levels in-vitro, indicating mitochondrial alteration. Metabolomic profiling revealed consistent elevation of three lysophosphatidylcholines (LPCs 16:0, 18:0, 18:1) in cells exposed to all SSRIs except citalopram. We further observed elevated LPC levels in the cord blood of infants prenatally exposed to SSRIs compared to those who were not (LPC 16:0 sn1: β = 0.173, 95% CI = 0.011-0.334, p = 0.037; LPC 16:0 sn2: β = 0.175, 95% CI = 0.007-0.343, p = 0.042 and LPC 18:0 sn2 β = 0.174, 95% CI = 0.018-0.330, p = 0.029), with a dose-dependent correlation to autism (LPC 16:0 sn2: overall p = 0.01) and ADHD-related symptoms (LPC 16:0 sn1: overall p = 0.007; LPC 16:0 sn2: overall p = 0.002) at age two. INTERPRETATION: These findings provide insights into SSRI-induced molecular changes in human iPSC derived neural cell cultures and highlight candidate metabolites that were validated in a clinical cohort. This may warrant their further investigation as indicators of SSRI exposure and emphasise the need for exploring prenatal SSRI exposure effects and neurodevelopmental outcomes in a wider context of other more well-established liability factors, including genetic background. FUNDING: Vetenskapsrådet, Swedish Foundation for Strategic Research, Hjärnfonden, H.K.H. Kronprinsessan Lovisas förening för barnasjukvård, StratNeuro, Swedish Foundation for International Cooperation in Research and Higher Education, Karolinska Institutet and the European Research Council.