In the past decade the prevalence of autism has approximately doubled in diagnoses for children. In 2006, 1 in 110 children were diagnosed in the United States, and by 2010 it had increased to 1 in 68. For boys the diagnosis is much more common. The CDC states: “ASD is about 4.5 times more common among boys (1 in 42) than among girls (1 in 189)” (Found here). Experts say this is only partly because of a change in diagnosis criteria, and mostly because of some unknown factors in the way we live, the environment, or possibly something else.
The search for the cause of Autism has been a long and rigorous process, but not without its fruit. The vast amount of research for the developmental disorder has brought about knowledge of the disease that has related it in various ways to a dysfunction in the brain’s neurons from forming synaptic connections, much like schizophrenia. They are similar in that they are both now being considered brain development disorders, but they differ in their typical diagnosis age and symptoms: autism is diagnosed as a child, while schizophrenia symptoms usually develop in a person’s early 20s. The link between autism and schizophrenia include shared genetic risk factors, among other things. This is why it takes time to notice symptoms, because the development of the brain is apparently normal until certain parts of the brain continue to form their connections.
How a synapse is formed is dependent on many different molecules and genetic components that are found in neurons (these are cells in the brain that send electro-chemical signals that are responsible for the ability of the brain’s processing power). A synapse is the point of connection between two neurons that involve many different signal-chemicals (glutamate, dopamine and norepinephrine for example) and regulating-molecules such as GABA and enzymes. However, there are also physical structures that hold the neuronal synapses together, and chemicals that guide the direction of neurons to their proper locations to form new synapses. In autism, the processes involving all three of these factors: the chemical balance of signal and signal reception, the guidance of neurons, and the physical structures holding them together are though to be impaired because of chemical imbalances that exist since birth. During the first three years of life, those with autism have brain “overgrowth,” meaning that the number of neurons forming and neuronal connections it too high in certain areas of the brain.
Knowing what we know about autism so far, it seems like there is a lot of knowledge about how we could treat the brain for healthy development, but treatment is still severely limited. The true underlying cause of autism remains unknown, however certain genetic and environmental risk factors have been identified. There is no evidence that vaccines cause autism, and many studies showing that they do not, as stated by the CDC, and backed up by many studies. Some examples of correlated causes of autism include certain precription drugs while pregnant (valproic acid and thalidomide), being born to older parents, or even stress during a pregnancy. The root cause remains elusive.