The present invention relates to methods of treating a subject diagnosed with autism or an autism spectrum disorder, lowering the level of mercury in a subject determined to contain a high level of mercury, methods of lowering the level of mercury in a child diagnosed with autism, lowering the level of at least one androgen in a subject diagnosed with autism, lowering the level of mercury and the level of at least one androgen in a subject diagnosed with autism and methods of assessing the risk of whether a child is susceptible of developing autism.