Differential efficacy of olanzapine for deficit and nondeficit negative symptoms in schizophrenia.

OBJECTIVE: Atypical antipsychotic medications have generally been found to be more effective than conventional antipsychotics in the treatment of negative symptoms. Whether the benefits derived from the atypical agents are the result of improvements in primary versus secondary negative symptoms is unclear. The authors examined the effects of olanzapine on primary and secondary negative symptoms for patients with severe negative symptoms who did or did not have the deficit syndrome.
METHOD: Thirty-nine outpatients with schizophrenia and severe negative symptoms were assessed for the presence of the deficit syndrome and entered into a 12-week, open-label study of olanzapine. Positive and negative symptoms, extrapyramidal side effects, quality of life, and level of functioning of the patients were assessed at baseline and endpoint.
RESULTS: All 39 patients completed the 12-week protocol; 13 of the patients had deficit negative symptoms, and 26 had nondeficit negative symptoms. Patients who had nondeficit negative symptoms demonstrated improvements in positive and negative symptoms, level of functioning, and extrapyramidal side effects over baseline. In contrast, patients meeting criteria for the deficit syndrome improved significantly over baseline only in extrapyramidal side effects.
CONCLUSIONS: The results of this study suggest that olanzapine is efficacious for secondary negative symptoms in schizophrenia but fail to support the contention that olanzapine has a direct beneficial effect on primary negative symptoms.