In the United States, we've seen a fifteen-fold increase in autism diagnoses over the past two decades. In fact, it's currently estimated that almost 1% of US children have an autism-spectrum disorder (ASD), while the rates in US adults are largely unknown.
The causes of autism, however, remain unclear. Genetic factors, dysfunctional cell-to-cell communication, and even environmental factors such as teratogens (chemicals that cause birth defects) have all been implicated. Indeed, ASDs may be as unique as the people who live with them, and a one-size-fits-all explanation may never be sufficient. One thing we know for certain is that there has never been a legitimate link found between autism and vaccine use. The science simply does not support childhood vaccination as a causal factor.
In a special issue of Discover Magazine released earlier this year, five intriguing yet largely speculative causes of the disorder are discussed. From an autoimmune hypothesis to a model of impaired mitochondria, these provocative explanations challenge conventional wisdom, and may, in fact, open the door to a new way of thinking about ASDs. We have learned a lot about autism recently, and with each new discovery, the picture grows clearer.