Kaiser Permanente investigators say more research is needed to explain the connection
An analysis of parents and their children in communities across the country finds a greater likelihood of autism-related traits in children of mothers who experienced depression while they were pregnant. The Kaiser Permanente-led study used data from the federally funded Environmental influences of Child Health Outcomes (ECHO) program and was published August 1 in Autism Research.
The authors noted that the results don’t explain why there would be an association between autism-related traits in children and prenatal depression in mothers, but that future research might explore shared genetic associations with both disorders.
“Our study advances what is known about this key association and underlines the need to better understand why it exists,” said lead author Lyndsay Avalos, PhD, MPH, a research scientist with the Kaiser Permanente Division of Research. “Previous studies have focused on children who were diagnosed with autism spectrum disorder, but that may miss some children who have attributes that do not meet the threshold of an autism diagnosis. It is important to explore autism-related traits, because these social, communication, and behavioral attributes can affect a child’s development.”
Previous research has suggested a relationship between parental mental health symptoms and autism in children, said senior author Lisa Croen, PhD, who leads the Autism Research Program at the Division of Research. “I expected that we would see an association,” Croen said. “This adds to the body of knowledge and suggests directions for future research.”
Avalos added, “These findings also remind us of the importance of screening pregnant patients for depression, and of early screening for autistic traits in children whose mothers experienced depression during pregnancy.” Screening can lead to early intervention, she noted.
The findings also contribute to the evidence clinicians may weigh when considering how to treat depression in pregnant patients, Avalos said.
The study used data from 33 cohorts, or groups of parents and their children, who are part of the ECHO program at sites around the country. The main analysis included 3,994 parent-child pairs. The researchers focused on mothers who had been diagnosed with depression in pregnancy, and children up to age 12 who had documented autism-related traits.
The analysis found a greater likelihood of autism-related traits in children whose mother had prenatal depression, but no significant difference in the association between boys and girls. Prenatal depression was also associated with a 1.64 times greater likelihood of moderate to severe autism-related traits.
A secondary analysis looked at severity of prenatal depression and found a dose-response relationship, meaning that there was a stronger relationship between more severe maternal depression diagnosis and child autism-related traits.
The study could not examine any possible role of depression treatment with medications, as parents who had taken antidepressants were left out of the analysis.
The authors said there are several possible explanations for the association, including a shared genetic predisposition in mother and child. “Similar genetics have been found to be associated with depression and with autism spectrum disorder,” Croen said.
Another possible mechanism could be cortisol levels in the parent during pregnancy affecting amygdala volume in the child or vasal constriction in the placenta. High cortisol levels are associated with depression. However, these possible mechanisms require further research, the authors said.
The study was funded by ECHO, a nationwide research program supported by the National Institutes of Health and launched in 2016. ECHO investigators study the effects of a broad range of early environmental influences on child health and development.
Additional co-authors from the Division of Research included Jennifer Ames, PhD, Assiamira Ferrara, MD, PhD, Monique Hedderson, PhD, and Yeyi Zhu, PhD. The full list of co-authors is available in the study.
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About the Kaiser Permanente Division of Research
The Kaiser Permanente Division of Research conducts, publishes and disseminates epidemiologic and health services research to improve the health and medical care of Kaiser Permanente members and society at large. It seeks to understand the determinants of illness and well-being, and to improve the quality and cost-effectiveness of health care. Currently, DOR’s 600-plus staff is working on more than 450 epidemiological and health services research projects. For more information, visit divisionofresearch.kaiserpermanente.org or follow us @KPDOR.