Most of the older, typical antipsychotics (such as haloperidol) were first used in the 1950’s. They were designed to block the action of the neurotransmitter dopamine. These older antipsychotics are sometimes called conventional or first generation antipsychotics.
Most of the newer, atypical antipsychotics (such as risperidone) were developed in the 1970’s, although aripiprazole was not developed until the 2000’s. These second generation antipsychotics were designed to block or increase the action of one or more neurotransmitters including dopamine, serotonin, noradrenaline and acetylcholine. They were also designed to have fewer side effects than the older antipsychotics.
Risperidone was approved as a treatment for irritability associated with autistic disorder in children by the United States Food and Drug Administration (FDA) in 2006.
Aripiprazole was approved for the treatment of irritability associated with autistic disorder in children by the FDA in 2009.