The Canadian Agency for Drugs and Technologies in Health (CADTH) has undertaken an optimal use project to assess the clinical and economic impact of using atypical antipsychotic combination therapy, as well as high-dosing treatment strategies, in adolescents and adults with schizophrenia. The following key messages were identified from this review:

• When a patient with schizophrenia is not adequately responsive to an antipsychotic agent, increasing the dose (within the recommended range), or switching to a different antipsychotic agent is recommended– switching to clozapine should be considered as an option.

• High-dose strategies or combining atypical antipsychotic drugs with other antipsychotic agents are not known to be more effective and may be more harmful than treatment with a recommended dose of one antipsychotic agent.