Risperidone is an atypical anti-psychotic drug, used for the treatment of schizophrenia, bipolar disorder and autism. It's primary therapeutic benefit is the suppression of psychotic episodes, although it does little to affect other symptoms of the conditions it is used to treat. In addition, although it has less severe side effects than older anti-psychotics, it is still associated with weight gain, metabolic diorders, dyskinesia and neuroleptic malignant syndrome. It is also very dangerous for patients who are actually suffering from dementia, increasing their risk of stroke. It is also more expensive than older anti-psychotics, although it's price has decreased since it went off patent in 2003. It is available as a pill, liquid, and an injection which lasts two weeks.
Risperidone was developed in the late 1980s and was first made available in the marketplace in 1993 after it was approved for the treatment of schizophrenia. It was soon the only drug that was approved for use of adolescent schizophrenia, which until that time had no approved treatment. It was approved for use for bipolar disorder in 2003 and for autism in 2006.