The "neuroleptic" antipsychotic drugs. 1. Mechanisms of action

The antipsychotic drugs have provided effective and relatively safe treatment of schizophrenia, paranoid illnesses, and manic-depressive conditions marked by psychotic features. These agents are sometimes called "neuroleptic," as virtually all produce signs of extrapyramidal neurologic disorders in addition to their antipsychotic actions; in part, evidently, the neuroleptic effects are an artifact of the means of screening of potential new agents. These agents have a strong and selective antagonistic action on synaptic mechanisms in the brain mediated by dopamine as a neurotransmitter. This antidopamine action almost certainly contributes importantly to their parkinsonism effect (basal ganglia) and their prolactin-elevating (hypothalamic) effect; in addition, antipsychotic actions may be mediated by antidopamine effects, possibly in limbic and other forebrain centers.