Visual memory of black and white male heroin and nonheroin drug users.

Although investigators have established that compulsive polydrug abuse adversely affects intellectual efficiency, the effects of prolonged heroin use remain unclear. The issue was assessed by comparing levels of intellectual functioning, as measured by the Raven Progressive Matrices, with expected levels of visual memory, as measured by the Benton Revised Visual Retention Test (BVRT). Whereas substance abusers scored within the average range of intelligence on the Progressive Matrices, the means of both heroin addicts (n = 467) and polydrug abusers (n = 310) on the BVRT were 2 SD below expected performance. Significant differences found in analysis of covariance and multiple regression models were not attributable to either demographic factors (age, education, socioeconomic status) or personality differences (as measured by MMPI scales). Like polydrug abusers, heroin addicts evidence interference in immediate, short-term memory, confirming earlier findings of marked perceptual disturbances among detoxified addicts. Unlike earlier findings, the results revealed significant ethnic differences. A need for establishing black norms is indicated for the BVRT and perhaps for other neuropsychological assessment procedures that lack ethnic norms. Additional research on shortand long-term memory among substance abusers is suggested.