ABSTRACT
Substance use disorders, including substance abuse and substance dependence, are the most common comorbid disorders in schizophrenia. Substance use disorders tend to have an early age of onset often preceding the development of major psychiatric disorders, can precipitate an earlier age of onset of psychosis, and contribute to a worse course of psychiatric illness, especially if they are not successfully treated. The accurate identification of substance use problems presents a major challenge to clinicians assessing and treating schizophrenia. All commonly used psychoactive substances can influence cognitive functioning, depending on drug type, duration of use, and nutrition status while abusing. Thus, the failure to accurately detect substance abuse in a person with schizophrenia can lead to inaccurate interpretation of neurocognitive performance. Clinicians working with clients with schizophrenia need to be familiar with the problem of substance abuse, have the skills and tools for assessing substance use and related problems in this population, and for incorporating relevant information about substance use into their interpretation of clients’ cognitive strengths and weaknesses.
