NEUROPSYCHOLOGICAL IMPAIRMENT IN OPIATE ADDICTS: RISK FACTORS *

The relationship between neuropsychological impairment and opiate addiction has been infrequently studied and the results have been contradictory. In a multi-center collaborative study of polydrug abuse, Grant et al. found that 37% of poly-drug users, many of whom used opiates, showed neuropsychological deficits based on clinician’s ratings of test results using the HalsteadReitan Neuropsychological Battery.l Risk factors for impairment included heavy use of CNS depressants and opiates, increased age, poorer academic achievement, and a history of CNS related medical events and developmental difficulties such as general anesthesia, or learning disabilities. These findings support earlier pilot investigations,2! 3 which also reported a high incidence of neuropsychological impairment (45% to 64% ) in multiple drug abusers following their entry into treatment. Another recent study found opiate addicts to have marked perceptual disturbances on the Bender Gestalt Test.4 In contrast, four studies5-8 have failed to detect any differences in neuropsychological status between polydrug users or opiate addicts and normal controls. The most recent of these investigations 5, are well-designed studies which employ either the extensive and widely used Halstead-Reitan Battery or selected tests from that battery.6 The present study is designed to extend previous work in this area by evaluating neuropsychological functioning of opiate addicts with an abbreviated, economical battery of tests that could be used more routinely for detecting neuropsychological impairment in clinical programs. In earlier studies, neuropsychological tests revealed deficits which were not found by medical history interviews or gross neurological exams, since evidence of a neurological disorder was an exclusion criterion for these investigations.lS3 If, as some studies suggest, a substantial number of addicts do manifest signs of neuropsychological impairment, then detection of these deficits may be important for treatment planning. Grant, et al. have suggested that “persons with such deficit might respond better to highly structured, problem-oriented interventions in which communications are simple and straightforward than to therapies producing high emotional arousaL”1 (p. 183) Rehabilitative efforts also may need to address limitations in an individual’s ability to learn and change that may be uncovered through the use of a neuropsychological test battery.