Autism could be triggered in genetically susceptible individuals by very low dose of anti-depressants or other chemical found in the water supply, found researchers from the University of Idaho in the US. Experts made this discovery by examining the genetic pathways of fish swimming in water infected with psychoactive drugs.
The fish was exposed to two types of anti-depressants, Prozac and venlafaxine and a drug which is used to control seizures, known as carbamazepine. They compared the concentrations of anti-depressants with the highest estimated environmental levels. They found patterns of gene activity in the fathead minnows that imitated those seen in humans vulnerable to the developmental disorder.
Lead author Dr Michael Thomas , stated while others have envisaged a causal role for psychotropic drugs in idiopathic autism, they were astounded to find evidence that this might happen at very low dosages, such as those found in aquatic systems. The genetic pathways affected were the same as those linked to idiopathic autism spectrum disorders, whose cause is unknown.
Autistic spectrum disorders start in infancy and last through maturity. Symptoms include problems with social interaction, an impaired ability to communicate and unusual patterns of thought and physical behavior. There is no cure for ASD but a wide range of treatments can help improve symptoms. The number of cases of ASD has increased over the last twenty years.
The discovery could radically alter treatment for one in one hundred children who have autism and improves understanding of doctors of how to prevent and treat the disorder. Autism spectrum disorder was caused by a combination of inherited and environmental factors, believe experts.
The study findings were published in the online journal Public Library of Science ONE.