Psychopharmacological treatment for schizophrenia: less is more.

Antipsychotic polypharmacy in the treatment of schizophrenia is more common in China and other Asian countries than in Western countries. The reasons for this are unclear, but it may be related to an unsubstantiated belief among clinicians that multiple medications are more likely to achieve the desired clinical outcome. Antipsychotic medications are the mainstay of treatment for individuals with schizophrenia, but the use of antipsychotic polypharmacy and of high dosages of antipsychotic medication are associated with substantially increased risks without conferring improved clinical outcomes. It is generally accepted that high dosages of antipsychotic medications and the simultaneous use of multiple antipsychotics are associated with an increased prevalence, duration, and severity of adverse drug effects. More recent evidence also suggests that antipsychotic polypharmacy and the associated high overall dosage of antipsychotic medication lead to excessive striatal D2 receptor occupation (resulting in tolerance and drug withdrawal problems) and exacerbation of the impaired synaptic plasticity seen in schizophrenia (magnifying the cognitive impairment associated with the condition). Clinicians need to apply the 'less is more' principle in the psychopharmacological treatment of schizophrenia.