Severity of neuropsychological impairment in cocaine and alcohol addiction: association with metabolism in the prefrontal cortex.

We used exploratory and confirmatory statistical approaches to study the severity of neuropsychological (NP) impairment in 42 crack/cocaine addicted subjects and in 112 comparison subjects (40 alcoholics and 72 controls). Twenty neuropsychological test indices most reliably defining predetermined cognitive domains were submitted to exploratory factor analysis. A four-dimensional model of neurocognitive function was derived: Verbal Knowledge, Visual Memory, Verbal Memory, and Attention/Executive functioning accounted for 63% of the variance.