New research this week points to a link between the use of selective serotonin reuptake inhibitors (SSRIs), a type of antidepressant, and the occurrence of autism in unborn kids. Another study found that among twins, the environment plays a bigger role in the development of autism than genetics which is a game changer considering past investigation into autism cause factors.
Over the past 30 years, the number of children with autism has increased from about 4 in 10,000 to about 40 in 10,000.
First off, research led by Kaiser Permanente Northern California reviewed the medical records of more than 1,600 children, 298 of whom had autism spectrum disorders (ASDs). They found that the risk of having a child with autism spectrum disorder was about twice as high among women who took SSRIs in the year before delivery. That risk was even four times higher in women who took SSRIs during their first trimester. SSRIs include such well-known brands as Prozac, Zoloft, Paxil and Celexa.
But though these numbers may seem alarming, the authors warn that they shouldn't be over-interpreted. Catherine Lord, director of the University of Michigan Autism and Communication Disorders Center in Ann Arbor states:
"As a general practice, I believe most [primary care physicians] discourage women considering pregnancy to avoid using medications that are not necessary, but the benefits of SSRIs in treating depression and as alternatives to other measures have to be weighed on an individual basis."
The researchers and other autism experts also stress the importance of balancing the needs of a depressed mother against the harm that could be done to the fetus by SSRIs.
Dr. Shlomo Shinnar, professor of neurology, pediatrics and epidemiology and population health at Montefiore Medical Center in New York continues:
"Major depression is a serious disease that needs treatment and the associations [in this study], while statistically significant, are not sufficient to change that."
Aside, past studies have estimated about 90% of the risk of autism is attributable to genetic factors. However, researchers at the Stanford School of Medicine in Palo Alto, California compared 192 sets of twins in cases in which one had an autism spectrum disorder and the other did not and made an interesting discovery.
The study explains:
"The results suggest that environmental factors common to twins explain about 58% of the liability to autism. Although genetic factors also play an important role, they are of substantially lower magnitude than estimates from prior twin studies of autism."
While more and more research is contributing to the understanding of where autism fits in the causal debate, there is still a lot left to learn about precisely what genetic and environmental factors are and whether or not they interact.
Sources: Archives of General Psychiatry Article 1 and Archives of General Psychiatry Article 2
Written by Sy Kraft