Experts today continue to look for potential causes of autism (also known as autism spectrum disorders or ASD) as the prevalence of autism appears to be increasing. The time of infancy has been an area of focus since parents have observed ASD symptoms begin around the time of vaccinations. Researchers are also turning their attention to the time of pregnancy and medications to treat prenatal depression as a possible cause of autism.
Autism Statistics Show an Increase in Rates of ASD
It is clear that autism is increasing dramatically in the previous decade. Statistics in the United States report autism is occurring in about one out of every 91 children, or roughly 1%. Reported rates of autism in Europe indicated that children diagnosed with autism spectrum disorders (ASD) are 12 in every 1,000 children. While many believe that the increasing rates of autism could be due to increasing knowledge about diagnostics, others wonder if the increase in autism might be explained by increased exposure to environmental or lifestyle hazards.
The Search for a Cause of Autism Has Resulted in Removal of Thimerosal from Vaccinations
One of the areas of focus in the search for the cause or causes of autism has centered around vaccinations. The largest area of concern has been with the preservative thimerosal used in many routine vaccinations. As a result of growing consumer concerns, thimerosal was removed from all vaccinations except the influenza vaccine in 2001. However, even after thimerosal was taken out of vaccinations, the numbers of children being diagnosed with ASD have continued to climb.
Researchers Look to Causes of Autism in Pregnancy
New information centering around exposure during pregnancy may shed light on a possible cause of autism. Researchers in Switzerland are examining the effects of large amounts of serotonin on the brain functioning of offspring in animal studies. While there is no hard evidence yet, researchers have seen altered brain functioning and abnormal levels of oxytocin in the offspring of female rats given large quantities of serotonin.
The most widely prescribed antidepressants are in the family of medications known as selective serotonin reuptake inhibitors or SSRIs. These antidepressants include Zoloft, Paxil and Prozac. Since SSRIs are frequently prescribed to women suffering from prenatal depression, some of the research shows altered brain functioning from high levels of serotonin and the rates of both prenatal depression and autism are increasing, this theory seems to hold up.
Once this research is completed, perhaps we will have one missing link to another possible cause of autism that may have its roots in pregnancy in the use of SSRIs to treat prenatal depression.
References:
Hadjikhani, H, "Serotonin, pregnancy and increased autism prevalence: Is there a link?", Med Hypothesis, December 15, 2009.
Brenda Lane - Brenda Lane is a published author, Lamaze certified childbirth educator, DONA certified birth doula and approved birth doula trainer.
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