New research links autism to testosterone levels in children.I just read an interesting article by Dr. Baron–Cohen who is a professor of developmental psychology and the director of the Autism Research Centre at the University of Cambridge, England. He is the principle architect of a theory which suggests that autism is linked to in utero exposure of the fetus to very high levels of testosterone.
This interesting hypothesis is that these very high levels of in utero testosterone can lead to extreme masculinization of the brain and the mind of the newborn. In Dr. Baron-Cohen’s words, “autism can be thought of as a case of extreme male brain”. This seemed fascinating to me, so I continued to read on. According to Dr. Baron-Cohen, the hormone testosterone and the genes that regulate testosterone during fetal development may be part of the link to the cause of autism. Although it is known that autism is likely due to complex and multifactorial issues, Dr. Baron-Cohen has found that fetal testosterone levels are typically twice as high in males as in females, and testosterone levels may vary up to 20 times in male fetuses. Given that the prevalence of autism spectrum conditions is about 1% in the general population, and that classic autism has a male: female ratio of 4:1, and Asperger’s syndrome is 9:1, the increased testosterone levels may be significant. Dr. Baron-Cohen has been conducting an ongoing study looking at 235 developing children whose fetal testosterone levels were known from maternal amniocentesis. He has followed them for 8 years and had parents rate their children for autistic traits. He found that the number of autistic traits a child displayed correlated with their fetal testosterone level, regardless of their sex. He also reported that earlier studies done on these children at 12 months of age, showed that those babies with higher testosterone levels were less likely to make eye contact with the mothers, and at age 2 these children had more limited vocabulary and language development than did those infants with lower fetal testosterone levels. So, many of the hallmarks of autistic spectrum disorders include social and communication difficulties, narrow interests, and extreme need for routine. Many would view these characteristics as being extreme “male” interests and behaviors. Does this in any way relate to those higher fetal testosterone levels? Are these gender differences due to cultural and social influences? These are very interesting questions and will need even more study. Dr. Baron–Cohen and other investigators will need to continue to research this very important, yet preliminary hypothesis, to see if they continue to find a correlation between fetal testosterone levels and autistic symptoms. Any information that brings us closer to solving the puzzle of autism is very exciting. I look forward to reading further data as it becomes available. That's your daily dose for today. We'll chat again tomorrow. Send your question or comment to Dr. Sue!