Maternal whole blood serotonin levels are associated with cognitive ability and core symptoms in children with autism spectrum disorder

Background: Biomarker and neuroimaging findings implicate the serotonin (5-HT) system in autism spectrum disorder (ASD). Recent findings in mice indicate that the maternal 5-HT system influences embryonic neurodevelopment.

Methods. Whole blood serotonin (WB5-HT) levels were obtained from 181 children diagnosed with Autism Spectrum Disorder, 93 of their fathers and 106 of their mothers. Standardized assessements were used to evaluate cognitive, behavioral, and language phenotypes.

Results. After correcting for proband age, multiple regression demonstrated a significant relationship between maternal WB5-HT and nonverbal IQ (F(2,101) = 4.891, P = .009), overall adaptive function on the Vineland Adaptive Behavior Scales-II, (F(2,99) = 4.220, P = .018), and overall standardized language score on the Peabody Picture Vocabulary Test-4, (F(2,71) = 3.323, P = .042). Proband WB5-HT was not associated with phenotype on any outcome measure. Latent class analysis identified a three-class structure in the assessment data, describing children with low, intermediate, and high severity across measures of behavior, cognition, and adaptive function. Mean maternal WB5-HT differed across classes but proband WB5-HT did not, with the lowest maternal WB5-HT levels seen in the highest severity group, Welch's F(2, 32.457) = 16.948, p