Cognitive Deficits in Schizophrenia and Alcoholism: A Review of the Evidence and Findings on the Effects of Treatment on Cognitive Functioning in Patients With Dual Diagnoses

Abstract

Objective: Although cognitive deficits have been carefully studied in both schizophrenia disorders and alcohol use disorders, comparatively little is known about cognitive deficits in patients with dual diagnoses of schizophrenia and alcohol use disorders. The main objectives of this article are (a) to review the literature on cognitive functioning in patients with dual diagnoses of schizophrenia and alcohol use disorders, and (b) to summarize the studies that have examined the effects of treatments on cognitive functioning in patients with these dual diagnoses. Methods: We identified and reviewed 10 studies that examined cognitive functioning in patients with schizophrenia and alcohol use disorders. We also identified and reviewed three studies that reported on treatments for cognitive deficits in patients with dual diagnoses of schizophrenia and alcohol use disorders. Results: Overall, patients with dual diagnoses of schizophrenia and alcohol use disorders were more cognitively impaired than those with a single diagnosis of schizophrenia or alcohol use disorders. The literature on the effects of treatment on cognitive functioning in patients with dual diagnoses is very limited, and the results indicate no effects of pharmacological treatments on cognitive functioning despite improvement in psychotic symptoms and/or abstinence from alcohol. Conclusions: There is a need for more systemic and rigorous study of cognitive deficits and their treatments in patients with dual diagnoses of schizophrenia and alcohol use disorders.

Keywords:

• dual diagnosis
• schizophrenia
• alcohol dependence
• alcohol use disorders
• cognitive functioning
• treatment

ACKNOWLEDGMENTS

Support was provided by VISN I Mental Illness Research Education and Clinical Center (MIRECC), and the VA Alcohol Center.