Attention and memory in illicit amphetamine users: comparison with non-drug-using controls

Area of Science:

• Neuroscience
• Psychology
• Addiction Research

Background:

• Previous research indicated neuropsychological deficits in amphetamine users.
• The extent and severity of these deficits require further clarification.

Purpose of the Study:

• To determine the extent of neuropsychological impairment in amphetamine users.
• To compare amphetamine users with varying dependence levels to a non-drug-using control group.

Main Methods:

• Participants included amphetamine users categorized by low (n=15) or high (n=11) dependence using the Severity of Dependence Scale (SDS).
• A control group of non-drug users (n=9) was also included.
• Neuropsychological functioning was assessed using the Wechsler Memory Scale-Revised (WMS-R).

Main Results:

• Highly dependent amphetamine users performed significantly worse (approx. 0.5 SD) than controls on verbal memory, attention/concentration, and delayed recall.
• Amphetamine users with low dependence did not exhibit significant impairments compared to controls.

Conclusions:

• Severe amphetamine dependence is associated with measurable deficits in specific cognitive functions.
• Mild amphetamine dependence does not appear to result in significant neuropsychological impairment.
• Findings highlight the dose-dependent and severity-dependent nature of cognitive effects in amphetamine users.