As the prevalence of autism grows, a growing amount of research is being done to help find the cause of and treatments for the disorder. Afflicting nearly one out of every 68 children, autism is increasingly more widespread among boys than it is in girls. With an estimated one in 42 boys living with autism in the United States, new research suggests a link between prenatal antidepressant drug use among mothers and the development of autism in their sons.
The study, out of the Johns Hopkins Bloomberg School of Public Health in Baltimore, was published by the journal Pediatrics. Dr. Rebecca Harrington, along with a team of her peers, researched the relationship between selective serotonin re-uptake inhibitors, or SSRI’s, use during pregnancy and the odds of autism spectrum disorder and developmental delays in males.
Drawing from data collected from 966 pairs of mothers and children, 800 of which were boys, the study observed the differences between 492 children with ASD, 154 with DDs, and 320 children that had typical development. The mothers were interviewed based on questions regarding prenatal SSRI usage, maternal mental health history, and information about there socio-demographics. The researchers found that children who were categorized under typical development, the prevalence of antidepressant usage was the lowest. There did not seem to be any significant difference in exposure to SSRI’s among TD children and children with autism or developmental delays. However there was a notable increase among boys with ASD or DD versus boys who were developing normally.
The conclusion among the research team was that it appeared for boys that exposure to SSRI antidepressants prenatally seemed to influence the likelihood of autism and other types of developmental delays. Co-author of the study, Li-Ching Lee, explained that prenatal SSRI exposure was nearly “three times more likely in boys with autism,” which is especially so when exposure occurs during the first trimester. Lee also mentioned that in order for the results to be considered more accurate, a greater number of girls would need to be tested.
While the study failed to prove a direct relationship linking boys who have autism and the use of antidepressants by their mothers during pregnancy, there seemed to be a strong correlation between the two. SSRI’s such as Prozac, Lexapro, Paxil and Celexa all increase the levels of serotonin in the mother which in turn permeate the placental wall and increase the level of the hormone within the fetus. It has been found among children with autism that around a third had serotonin levels that were above average. Medical research suggests that the presence of high levels of serotonin in babies may result in abnormal brain circuitry development, which might influence the progression of autistic related symptoms.
In the case of autism, there in no one cause of the disorder. Autism takes many forms and is associated with a variety of rare gene mutations. Some that have been found of being capable of producing autism on their own. However autism is believed to most likely be caused most often by a combination of autism gene mutations and environmental factors which impact brain development in early childhood.
Non-genetic factors also appear to play a significant role during both pregnancy and birth. These factors include: advanced ages of both the mother and father, maternal illness during pregnancy and complications during childbirth such as periods of oxygen deprivation for the baby as it is being delivered. The use of antidepressants during pregnancy only adds to the list of non-genetic factors that elevates the risk of developing autism.
About 13 percent of women experience depression during pregnancy. Lee explains that the decision of whether or not to treat depression in expecting mothers is complex because there are so many factors to consider. Although experts argue that the overall risk of having a child with autism is still very low, the results of this study help contribute to the ongoing debate which puts forth that SSRI’s use among prenatal women has been linked to an increased incidence of autism in their children.
Director of the Autism and Obsessive-compulsive Disorder Program, Dr. Eric Hollander, articulates that the study’s findings should not alarm expecting mothers. The association is modest at best, and currently there is only a one percent risk of having a child with autism. Although the use of SSRI’s during pregnancy should not be taken for granted, Hollander argues that if other research studies end up validating SSRI use during pregnancy does cause a higher risk of autism in boys, even then it will still raise the risk to three percent.
While the current research does seem to show a link between autism in males and the use of prenatal antidepressants among their mothers during pregnancy, these findings should not overshadow the dangers of prenatal depression. This disease during pregnancy is unhealthy for both mother and baby and if it is left untreated, could be potentially life threatening. What is suggested is that women discuss the risks of antidepressant use during pregnancy so that they are fully aware of the potential risks involved.
By Natalia Sanchez