Abstract
There are substantial differences between individuals in the effects of antipsychotic drugs in the treatment of schizophrenia. This is apparent in symptom response, as well as in the emergence of side effects, such as tardive dyskinesia or weight gain. Genetic variation is likely to contribute substantially; in the past decade genetic polymorphisms in candidate genes have been identified which are associated with these individual differences. Whether pharmacogenetics will prove valuable in antipsychotic drug discovery is unclear, although it is already elucidating mechanisms of antipsychotic drug action, and genetic testing may well lead to a future of individualised drug treatment.