MEMORY IMPAIRMENT IN METHAMPHETAMINE DEPENDENT PATIENTS

Abstract

The authors examined the verbal memory and visual memory of 19 patients with methamphetamine dependence and 18 normal controls to assess the memory impairment due to the use of methamphetamine. There was no significant difference in the verbal memory, but a significant difference was detected in the visual memory. The results that the methamphetamine selectively impairs visual memory seem to be because visual memory tasks are more sensitive to the damage of the executive function.

Keywords:

• executive function
• methamphetamine
• verbal memory
• visual memory

Notes

The pattern of the results on the statistical analysis was almost identical when the analysis was performed using the data from the 17 methamphetamines users who completed both the verbal and the visual memory tests and the data from their corresponding normal control subjects. The authors used the data from 19 users to increase the statistical power.

Because of the difficulty in finding normal control subjects who matched each of the methamphetamine users in age and for the block design score, the correlated t-tests were performed for the verbal memory scores and the visual memory scores with using the data of the subjects who were matched for the corresponding confounding variable, that is, age for the verbal memory and the block design score for the visual memory. That is why the sample size for the verbal memory and the visual memory are different.