The impact of heroin on visual memory

Heroin abuse can lead to organic damage of cerebral structures, including sequels in cognitive and affective sphere, which are in positive relation with the duration of substance usage. Memory is one of the cognitive functions which is highly sensitive to opiate toxic effects. The aim of this research was determination of heroin impact on the visual memory of addicts, as well as the existence of specific relation of potential deficiencies in visual memory with the duration of substance use.

The research included 90 examinees, divided into three groups, depending on the duration of heroin intake. We used questionnaire for basic socio-demographic and addictological traits of examinees; Wechsler's scale for the assessment of the intelligence and Visual Memory Test (TVP), for the assessment of the visual memory.

The achievements of heroin addicts with different duration of the substance abuse differ significantly (F = 1.83; df = 12; p < 0.05). Total number of errors examinees make in the first series of TVP (immediate visual memory) grows, almost linearly in the function of the duration of heroin abuse (p < 0.05), but in neither of groups meets criteria for the visual memory impairment. Deficiency of the delayed visual memory occurs in examinees who use heroin for one (total number of errors = 6.46; participation of typical organic errors = 31.7%) and longer than five years (total number of errors = 7.66; participation of typical organic errors = 26.7%). Univariate covariance analysis separates the average daily dosage of heroin as the most significant variable that contributes to the expression of the aforementioned deficiencies (F = 4.21; df = 2; p < 0.05).

Heroin abuse leads to damage of delayed visual memory, whereby for the observed effect intake of the substance for a period longer than one year is necessary.