How do antipsychotic medications work?

Antipsychotic treatments mainly seem to control psychotic episodes by reducing the effects of chemicals in the brain. Older conventional (typical) antipsychotics reduced the levels of a chemical called dopamine and this was believed to result in the improvement of positive symptoms. However this meant that they were not as effective against negative symptoms and they were also associated with unpleasant movement disorders known as Extrapyramidal (EPS) disorders. The atypical (newer) antipsychotics work on dopamine but also have an action on another chemical, serotonin. This dual action means that they work on a broader range of symptoms and also appear to have fewer of the troublesome movement disorder side-effects.

New approaches have led recently to the development of longer-acting forms of oral atypical antipsychotics. These are aimed at further improving schizophrenia treatment by being more convenient for patients as they need to only take their medication once per day, yet they still work effectively and may be well tolerated.

Some antipsychotic drugs can be sedating, which can be useful when treatment is started, especially if the patient feels agitated. However the effect of antipsychotic drugs is not necessarily related to the sedative effect; and antipsychotics do not have to sedate a patient to be effective.