The impact of regular ecstasy use on memory function

Aim  To assess memory impairment in a group of regular users of ecstasy compared with a group of regular users of cannabis, after accounting for possible confounding factors such as other drug use, premorbid intelligence and psychopathology.
METHOD  Comparative and regression analysis was used to determine the presence or absence of a difference in memory function between 40 regular ecstasy users and 37 regular users of cannabis, who were interviewed at the National Drug and Alcohol Research Centre in Sydney, Australia. Regression analysis was used to find associations between life-time exposure to ecstasy use and memory performance. Memory function was assessed using an age-standardized memory test. Other scales were used to assess premorbid intelligence, physical and psychological health, drug withdrawal and other drug use.
Results  Initial comparative analysis showed a trend towards a significantly poorer performance by the regular ecstasy-using group on the 'auditory immediate memory' and 'auditory delayed memory' indices. When regression analysis was performed an estimate of verbal intelligence was found to be the most predictive of most memory indices including 'auditory immediate memory' and 'auditory delayed memory'. Life-time exposure to ecstasy was not predictive of the memory indices. The current frequency of cannabis use was found to have some predictive effect for immediate and delayed visual memory.
Conclusion  This study does not show memory impairment in a group of ecstasy users relative to cannabis using controls. The previously reported association of life-time exposure to ecstasy and memory was not found. The findings may indicate a confounding role of cannabis use, as has been recently reported.