DEPRESSION, SSRIs, and AUTISM RISK

Does Antidepressant Use During Pregnancy Increase The Risk Of Autism In Offspring?

By Lirio Sobrevinas-Covey, Ph.D.

​Recent findings:

1. From a recent population based large sample in Sweden (1):

§ Yes, antidepressant use during pregnancy increased the risk of ASD in children.

§ The risk occurred in ASD offspring without intellectual disability.

§ No increased risk was found in offspring with ASD with intellectual disability.

2. From an ongoing population-registered base in Quebec (2):

§ Yes, the risk for ASD was higher in offspring of mothers who used SSRIs (selective serotonin reuptake inhibitors​)​ during the second or third trimester of pregnancy.

§ The risk persisted after controlling for the effect of maternal depression.

COMMENT: A causal interpretation, that is, that antidepressant use causes autism in offspring cannot be inferred from these early data. Further, the risk that antidepressant use influenced the autism is estimated at less than 1%. The finding that the phenomenon was observed primarily in ASD offspring without intellectual disability suggests that the risk affects ASD persons previously

​diagnosed ​
as having Asperger’s syndrome. A possible implication is that a certain portion of cases of ASD could be prevented if antidepressants were not used during pregnancy.

BACKGROUND: A history of depression, one of the more prevalent psychiatric conditions, has been considered a possible risk factor for autism. Depression is a condition that is responsive to medication treatment (in addition to behavioral therapy). SSRIs (selective serotonergic reuptake inhibitor drugs), because of their demonstrated efficacy and safety, are a widely used treatment for depression. Serotonin has been shown to play a critical role in fetal brain development, thus, concerns have been raised regarding the manipulation of serotonin levels, a neurotransmitter which crosses the placental barrier, when taken by pregnant mothers. Thus, in the search for non-genetic factors (considered the main predictors of autism risk), antidepressant treatment during pregnancy was examined as a possible environmental factor influencing autism risk.

Of interest, the use of antidepressants during pregnancy has increased in the last several decades, parallel in some way to the rise in the incidence of autism in those years. The clinical dilemma therefore is whether to treat depression or not during pregnancy with SSRIs (or any other antidepressant). Existing research is limited. The mechanisms underlying the observed associations are unclear. Because depression during pregnancy by itself has been found to increase the risk for autism, non-pharmacological measures treatments should be considered. Understanding prenatal factors such as medication of mothers’ conditions during pregnancy could identify modifiable targets for preventing the incidence of ASD.

1. Dheeraj R, Lee BK, Dalman C, et al, British Medical Journal, 2013, Apr 19; 346

2. Boukhris T, Sheehy O, Mottron L, Bérard A, JAMA Pediatr. 2015 Dec 14:1-8.