Current strategies for the development of novel antipsychotic drugs.

While classical neuroleptics are characterized by dopamine D(2) antagonism, this is also considered to be the cause of their neurological side effects. In recent years, novel antipsychotic drugs with improved efficacy, devoid of extrapyramidal effects are being developed. The mechanisms of action of these new atypical antipsychotics can be classified into three general groups: a) binding to D(2) together with non-dopaminergic receptors, b) interaction with dopamine receptor subtypes other than D(2) and c) selective binding to non-dopaminergic systems, such as glutamatergic, sigma, neurotensin, and cannabinoid.