Can there possibly be environmental factors that contribute to autism or spectrum disorders? Recent research suggests this may be the case. A study published November 2010 in Archives of General Psychiatry researched 192 identical and fraternal twins where at least one twin had classic autism, and in many other cases the sibling had a less severe form of autism or autism spectrum disorder.
It is important to note that identical twins share 100% of genes where fraternal twins share 50% of genes. Comparing identical and fraternal twins allowed the researchers to not only measure genes but also the role of environmental causes. In this study 77% of identical male twins and 50% of female identical twins had autism or autism spectrum disorder compared to 31% of male fraternal twins and 36% of female fraternal twins. When reviewing the results above, mathematics and statistics concluded that 38% of autism or autism spectrum disorder attributed to genes and 58% of the cases shared environmental factors. This is much different than past research concluded 90% of autisms or autism spectrum disorders were attributed to genes.
A second article suggests there is an elevated risk for autism in mothers who took popular antidepressants a year before delivery and in the first trimester of pregnancy. The risk is still considered low statistically suggesting a risk of 2.1% when taking the antidepressant a year prior to delivery and 2.3% when taking the antidepressant the first trimester.
Decades ago psychiatrists suggested that lack of maternal warmth could be a cause of autism. It has also been suggested that prenatal age, multiple pregnancies, low birth weight, exposure of medications, and maternal infection can also contribute to autism. Other studies have suggested that exposure to antibodies and specific fatty acids in mother’s milk can also be associated with autism.
I look forward to more research on this subject. As the rate of autism has increased faster than researchers say genes evolve, there must be another piece to the puzzle. I am also interested to see more research on nutritional parameters and autism. Stay tuned to learn more about effective “diets” for autism.