Electroconvulsive therapy in treatment-resistant schizophrenia: prediction of response and the nature of symptomatic improvement.

BACKGROUND: The clinical features of patients with schizophrenia who respond to electroconvulsive therapy (ECT) are uncertain. There is a longstanding belief that the duration of illness and/or the presence of affective symptoms associate with good prognosis. There is also little information on the nature of symptomatic improvement with this treatment.

OBJECTIVES: We examined the demographic and clinical history features associated with response, the symptom profile predictive of response, and the profile of symptomatic improvement.

METHOD: Using a standardized protocol, 253 patients with treatment-resistant schizophrenia were prospectively treated with a combination of ECT and flupenthixol.

RESULTS: Of this group, 138 patients (54.5%) met the response criteria. Independence of sex, longer duration of current episode, and greater severity of baseline negative symptoms were predictive of poorer outcome. Duration of illness had weak relations with outcome only among females. There were marked sex differences in other clinical features and symptoms associated with response. In contrast, no sex differences were observed in the nature of symptomatic improvement. Treatment resulted in marked improvement in specific positive symptoms, with an intermediate effect on affective symptoms and no effect or worsening of specific negative symptoms.

CONCLUSIONS: The findings challenge recommendations that long duration of illness or absence of affective symptoms portends poor response to ECT in patients with treatment-resistant schizophrenia. Sex may play a critical role in determining the features of the illness that predict outcome.