The need for individualised antipsychotic drug therapy in patients with schizophrenia.

Drug therapy for schizophrenia aims to both reduce symptoms in the acute phase and maintain long-term symptomatic remission during periods of stabilization. Atypical antipsychotic agents are the mainstay of schizophrenia therapy because of their improved tolerability, including a reduced likelihood of extrapyramidal symptoms, compared with conventional antipsychotics. However, responses to antipsychotic therapy are influenced by a wide range of factors, such as age, gender, race, comorbidities, genetics and social and environmental conditions, that make identifying the most appropriate antipsychotic treatment for each individual patients, an ongoing challenge for physicians. Tools that may be useful to assist clinicians in determining appropriate individual therapy include consideration of treatment moderators, which specify for whom or under what conditions a treatment works, treatment mediators, which are mechanisms by which a treatment achieves its effects, and cluster group analyses, which identify subsets of patients with similar characteristics. Further research is required to determine whether cluster groups of patients with schizophrenia can be identified based on treatment moderators and mediators, and whether antipsychotic prescribing based on consideration of these cluster groups leads to improved treatment outcomes.