Substance use and cognition in early psychosis.
OBJECTIVE
To determine the relation between substance use and cognition in individuals experiencing their first episode of psychosis.


METHODS
Prospective cross-sectional and longitudinal study.


METHODS
An Early Psychosis Treatment and Prevention Program, an outpatient clinic in a psychiatry department at a university-affiliated hospital.


METHODS
Individuals with a psychotic illness who were admitted to an Early Psychosis Program; 266 patients were assessed at initial presentation, 159 at 1 year and 90 at 2 years. Most were outpatients.


METHODS
The effects of substance use (alcohol, cannabis, hallucinogens, cocaine, stimulants) on cognition were assessed. Substance use was determined by DSM-IV criteria, and the Case Manager Rating Scale was used to determine the level of substance use. A comprehensive cognitive battery of tests was used, and the Positive and Negative Syndrome Scale for schizophrenia was administered to all subjects to determine levels of positive and negative symptoms.


RESULTS
Overall, both cross-sectionally and longitudinally, there were no significant associations between cognitive functioning and the use of various substances. Substance use was associated with higher positive symptoms.


CONCLUSIONS
Individuals with psychotic disorders who show mild-to-moderate abuse of substances, in particular alcohol and cannabis, do not exhibit more cognitive impairment than those who do not do use the substances. However, substance use may have other detrimental effects on the process of the psychotic illness.
Pencer
Alissa
A
Department of Psychology, University of Calgary, Calgary, Alta.
Addington
Jean
J
D000293:Adolescent; D000328:Adult; D003072:Cognition Disorders / Q000139:chemically induced / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D013287:Illicit Drugs / Q000009:adverse effects*; D008297:Male; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011594:Psychometrics; D011605:Psychoses, Substance-Induced / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D012559:Schizophrenia / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology; D012565:Schizophrenic Psychology; D019966:Substance-Related Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology
D013287:Illicit Drugs