J.A. Lieberman

Cognitive deficits are a fundamental feature of the psychopathology of schizophrenia. Yet the effect of treatment on this dimension of the illness has been unclear. Atypical antipsychotic medications have been reported to reduce the neurocognitive impairment associated with schizophrenia. However, studies of the pattern and degree of cognitive improvement with these compounds have been methodologically limited and have produced variable results, and few findings have been replicated. To clarify our understanding of the effects of atypical antipsychotic drugs on neurocognitive deficits in patients with schizophrenia, we have (1) reported on newly established standards for research design in studies of treatment effects on cognitive function in schizophrenia, (2) reviewed the literature on this topic and determined the extent to which 15 studies on the effect of atypical antipsychotics met these standards, (3) performed a meta-analysis of the 15 studies, which suggested general cognitive enhancement with atypical antipsychotics, and (4) described the pharmacological profile of these agents and considered the pharmacological basis for their effects on neurocognition. Finally, we suggest directions for the development of new therapeutic strategies.

OBJECTIVE: The authors conducted a review and meta-analysis of studies that compared the efficacy and tolerability of typical and second-generation antipsychotics for patients with treatment-resistant schizophrenia. METHOD: A systematic search revealed 12 controlled studies (involving 1,916 independent patients), which were included in the review. For the seven studies that compared clozapine to a typical antipsychotic, a meta-analysis was performed to examine clozapine's effects on overall psychopathology, response rate, extrapyramidal symptoms, and tardive dyskinesia. RESULTS: The meta-analysis confirmed that treatment-resistant schizophrenic patients have more favorable outcomes when treated with clozapine rather than a typical antipsychotic, as reflected by Brief Psychiatric Rating Scale total score, categorical response rate, Scale for the Assessment of Negative Symptoms score, Simpson-Angus Rating Scale score, and compliance rate. Clozapine also conferred benefits on the sickest treatment-resistant schizophrenic patients. Patients treated with olanzapine also had more favorable outcomes with regard to categorical response and compliance rates. CONCLUSIONS: In the aggregate, the results of a meta-analysis indicated that clozapine exhibits superiority over typical antipsychotics in terms of both efficacy (as measured by improvement in overall psychopathology) and safety (in terms of reduced extrapyramidal side effects). However, the magnitude of the clozapine treatment effect was not consistently robust. Efficacy data for other second-generation antipsychotics in the treatment of patients with refractory schizophrenia were inconclusive. There is, therefore, a growing need to consider new and different treatment strategies, whether they be adjunctive or monotherapeutic, for schizophrenia that continues to be resistant or only partially responsive to treatment.

OBJECTIVE: To examine the course and potential predictors of treatment response in the early phase of schizophrenia. DESIGN: Prospective study of an inception cohort. SETTING: Psychiatric division of an academic medical center with a suburban metropolitan catchment area. PATIENTS AND INTERVENTION: Seventy first-episode patients who had undergone four biologic assessment procedures (brain magnetic resonance imaging, behavioral response to methylphenidate hydrochloride, growth hormone levels, eye tracking) were treated with a standardized antipsychotic drug protocol until recovery. Response was measured in terms of psychopathology and degree of remission. RESULTS: Using survival analysis, the proportion of patients remitting by 1 year was estimated at 83%. Mean and median times to remission were 35.7 weeks and 11 weeks, respectively. No baseline demographic or psychopathologic measure significantly predicted time to or level of remission. However, males tended to be nonresponders to treatment and have diagnoses of schizophrenia rather than schizoaffective disorder. Brain pathomorphology and abnormal basal growth hormone significantly predicted time to remission. CONCLUSIONS: These results indicate that the antipsychotic treatment response of first-episode schizophrenics is better than chronic multiepisode patients and suggest that specific pathobiologic markers reflect pathophysiologic processes that mediate antipsychotic treatment response.