The effect of heroin on verbal memory

As a result of long-term heroin abuse we can see impairment of cerebral structures, that leads to specific psychopathological and neuro - physiological deficits in the cognitive and connative areas. There is a positive correlation between the mentioned deficits and the duration of heroin abuse. The memory is a cognitive function highly sensitive to toxic effects of opiates. The aim of this study was to establish the psychiatric and psychological consequences of heroin abuse, in the sense of verbal memory deficits, and the specific relation between mentioned deficits with the duration of abuse.

The research was devised as a prospective study, including ninety heroin addicts, divided into three groups, based on the abuse duration. The following instruments were used for data collecting: questionnaire, with basic social-demographic and addictive characteristics of subjects and Rey Test of Verbal Learning, a neuropsychological test for verbal memory estimation.

Only the examinees who have abused heroin for less than a year obtained scores within the domain of the expected performances within the part of the test which relates to the direct verbal memory, as well as, the part of the test that relates to delayed verbal memory. With regard to the mentioned criteria, the difference between examinees with different length of opiates abuse is statistically important (direct memory: F=2.706; p=0.063, delayed memory: F=2.538; p=0.045). With the increase of heroin abuse length the number of examinees with a rising learning curve is decreased significantly, and the number of examinees with a flat learning curve is increased (Chi-square=19.589; p=0.003).

Heroin abuse, lasting longer than one year, is connected with impairment of short-term and delayed verbal memory. The intensity of the mentioned effects is higher with addicts who use a higher daily dose of heroin.