The stability of neuropsychological test performance in a group of parenteral drug users

The stability of neuropsychological performance in a sample of drug abusers was investigatedfor a wide range of neuropsychological tests, using a test-retest paradigm with Idparenteral drug users. The battery administered included tests of general intellectualfunction, abstract reasoning, verbal memory, language, attention, visuospatial ability, set switching, speededperformance, and manipulative dexterity. Stability coefficients were of a moderate to high magnitude for most of the tests and were comparable to coefficients found in other studies of non-drug-users. Two exceptions, however, were the Selective Reminding Test and the Perdue Pegboard. Possible reasons for instability with these two tests are discussed. It is concluded that neuropsychological investigations of drug abusers can yield consistent and reliable data, although further studiesshould employ alternative and/or supplementary measures of verbal memory and motor function