NEUROPSYCHOLOGY OF DUAL DIAGNOSIS - UNDERSTANDING THE COMBINED EFFECTS OF SCHIZOPHRENIA AND SUBSTANCE USE DISORDERS

Empirical studies of cognitive functioning in patients suffering from schizophrenia and a substance use disorder are lacking Consensus exist s that schizophrenia is a neurobehavioral disorder with cognitive defi cits. With this ready explanation for cognitive impairment in schizoph renia, there exists the possibility that other treatable sources of co gnitive decline in schizophrenia, such as substance abase, may be igno red. The cognitive impairments (e.g., abstraction, selective attention , effortful processing episodic memory and denial of deficits/illness) and biologic abnormalities (e.g., reduced P300 amplitude, enlarged ve ntricles, and hypofrontality) common to both schizophrenia and substan ce use disorders are reviewed. Differences in the cognitive status of the disorders are also noted. Factors altering the cognitive status of these patients are discussed, and seven potential frameworks are offe red for conceptualizing the etiologic relation and cognitive impact of these disorders.