Clinicians treating patients with first-episode (FE) schizophrenia can draw upon the vast literature on the treatment of patients with multiple-episode schizophrenia. Studies with multi-episode patients, however, may not fully generalize to the treatment of FE patients. Studies with multi-episode patients typically recruit from hospitals or other acute care units, settings where patients usually have been either non-responsive or non-adherent to previous treatment, or mixtures of both. Studies of multi-episode patients therefore tend to include patients who are not fully responsive to treatment. Without the filter of prior treatment history, FE compared with multi-episode patients may show a broader range of treatment patterns, ranging from extremely good to very poor. Further, studies of FE patients may be very instructive about side effects, as the confounding effect of prior medication use is particularly important with side effects. Finally, data suggest that much of the deterioration (eg, more severe negative symptoms) associated with schizophrenia may occur during the 5 years following illness onset. Providing patients with better treatment at illness onset offers the hope of improving their long-term outcome.

FE studies do have limitations. Relatively few new cases of schizophrenia occur each year. The typically chronic course of schizophrenia results in a large number of patients with multi-episode schizophrenia for every FE patient at any one time. Recruitment for studies of FE schizophrenia compared with those of multi-episode schizophrenia is often more difficult given the smaller number of available patients. We systematically know less about the treatment of FE patients than we do about the treatment of multi-episode patients.