Identifier

etd-0417102-054620

Degree

Doctor of Philosophy (PhD)

Department

Psychology

Document Type

Dissertation

Abstract

The purpose of this study was to investigate the relationships between the severity of cocaine/alcohol use, neuropsychological functioning, and cerebral blood flow abnormalities. Cocaine users (n = 60) and control subjects (n = 13) were administered a battery of neuropsychological tests that yielded the following factors: Attention/Executive Functioning, Memory, Simple Motor, and Sensorimotor. Participants were assessed for decreased cerebral blood flow with single-photon emission computed tomography (SPECT). Examination of group differences indicated that cocaine users performed significantly worse than controls on the Memory and Sensorimotor factors. The frequency/duration of cocaine use, alcohol use, and a combination of both substances were evaluated to specify which contributed the greatest to reductions in cognitive functions. Increasing frequency of recent alcohol consumption was a significant predictor of worse performance on the Attention and Sensorimotor factors. Years of alcohol use was also significantly related to the Attention factor, whereas, greater duration of cocaine use predicted poorer performance on the Memory factor. Caucasian race was associated with better performance on the Attention/Executive Functioning, Memory, and Sensorimotor factors. The ethnic differences persisted after controlling for greater substance use among African-Americans. Increasing severity of total cerebral hypoperfusion contributed significantly only to the prediction of poorer performance on the Simple Motor factor. There was some evidence supporting the hypothesis that the severity of hypoperfusion worsens with increasing frequency of cocaine use. Moderate alcohol use appeared to be related to a reduction in severity of hypoperfusion. Overall, the results suggested that reductions in memory functioning in this group of cocaine users was specifically related to increasing duration of cocaine use, rather than to alcohol, or a combination of the two. Attention and sensorimotor functioning seem to be more reliant on the frequency of recent alcohol usage, contrary to the assumption that declines in these functions were due to cocaine among samples of cocaine-dependent patients. Findings suggested that simple motor performance was more affected by global hypoperfusion than the other cognitive functions. Future research is needed to evaluate whether more localized areas of cerebral perfusion deficits reveal a significant relationship between hypoperfusion and memory, attention, and sensorimotor functioning.

Date

2002

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Wm. Drew Gouvier

Included in

Psychology Commons

Share

COinS