Antipsychotic

Antipsychotics, previously known as neuroleptics and major tranquilizers, are a class of psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), principally in schizophrenia but also in a range of other psychotic disorders. They are also the mainstay, together with mood stabilizers, in the treatment of bipolar disorder. Moreover, they are also used as adjuncts in the treatment of treatment-resistant major depressive disorder.

While some research has shown that use of any antipsychotic is associated with smaller brain tissue volumes, including white matter reduction and that this reduction is dose dependent and time dependent, schizophrenia is itself a neurodegenerative disorder associated with reduced brain tissue volumes. A more recent controlled trial suggests that second generation antipsychotics combined with intensive psychosocial therapy may potentially prevent pallidal brain volume loss in first episode psychosis.

The use of antipsychotics may result in many unwanted side effects such as involuntary movement disorders, gynecomastia, impotence, weight gain and metabolic syndrome. Long-term use can produce adverse effects such as tardive dyskinesia, tardive dystonia, and tardive akathisia.

Prevention of these adverse effects is possible through concomitant medication strategies including use of beta-blockers. Currently, treatments for tardive syndromes include VMAT2 inhibitors.

First-generation antipsychotics (e.g. chlorpromazine), known as typical antipsychotics, were first introduced in the 1950s, and others were developed until the early 1970s. Second-generation antipsychotics, known as atypical antipsychotics, arrived with the introduction of clozapine in the early 1970s followed by others (e.g. risperidone). Both generations of medication block receptors in the brain for dopamine, but atypicals block serotonin receptors as well. Third-generation antipsychotics were introduced in the 2000s and offer partial agonism, rather than blockade, of dopamine receptors. Neuroleptic, originating from Greek: νεῦρον (neuron) and λαμβάνω (take hold of)—thus meaning "which takes the nerve"—refers to both common neurological effects and side effects.