Antipsychotic drugs for first-episode schizophrenia: a comparative review.

Increasingly, it is recognized that first-episode schizophrenia represents a critical stage of illness during which the effectiveness of therapeutic interventions can affect long-term outcome. In this regard, the advent of clozapine and subsequent atypical antipsychotic drugs held promise for improved outcomes in patients with first-episode schizophrenia, given the expectation of improved therapeutic efficacy and a more benign side effect burden compared with typical antipsychotic drugs. A growing number of large clinical trials have evaluated the merits of atypical antipsychotic drugs in the early stages of psychosis. A number of conclusions can be drawn from studies completed to date, with the caveat that data are either limited or unavailable for the antipsychotic drugs most recently approved by the US FDA. Studies of atypical antipsychotic drugs support data obtained with typical agents indicating that positive symptoms of psychosis are very treatment responsive and generally at lower doses than in chronic illness. It also appears that first-episode patients tend to stay on atypical antipsychotic drugs longer than on typical agents when all-cause discontinuation criteria are considered as the primary outcome measure. However, there are few differential advantages of clinical efficacy among the individual atypical antipsychotic drugs and there is little evidence to support distinct therapeutic advantages for negative symptoms or cognitive symptoms for atypical agents. Furthermore, while new-onset psychosis patients are particularly susceptible to extrapyramidal symptoms, they are also prone to gain weight and related metabolic adverse effects associated with many, but not all, atypical antipsychotic drugs. Recent data indicating that certain atypical antipsychotic drugs may have a sparing effect on cortical grey matter loss in first-episode schizophrenia is intriguing, given the potential long-term benefits. In summary, atypical antipsychotic drugs represent an incremental advance for patients in first-episode schizophrenia, especially in the area of neurological tolerability. However, metabolic concerns associated with many atypical agents along with limited benefits in cognition and negative symptom domains highlight the persistent therapeutic needs of these patients.