Deficits of long-term memory in ecstasy users are related to cognitive complexity of the task

Chapter 8 discusses how drugs affect the brain and behavior.  There is a great amount of evidence in animal studies that suggests that the drug methylenedioxymethamphetamine (ecstasy) causes lasting damage to regions of the brain involved in long-term memory.  However, there has been some variability when the memory performance of humans has been tested.  It is possible that this variance may reflect the complexity of memory tasks.  This study set out to use tasks differing in complexity to evaluate ecstasy-related deficits in human verbal memory.

Regions of the brain that are damaged by ecstasy include the hippocampus, frontal lobes and sensory areas.  These parts of the brain are critical in the process of retrieving long-term memories.  Therefore, in this study, researchers hypothesize that the more of these regions of the brain that are utilized to complete a verbal memory task, the more apparent that ecstasy-related deficits will be in users of the drug.  There were 3 samples used.  Sample 1 was comprised of 32 ecstasy users and 29 non-drug using controls, Sample 2 had 30 ecstasy users and 34 non-drug using controls, and Sample 3 had 33 ecstasy users, 32 cannabis controls, and 32 non-drug using controls. 

Sample 1 had to perform an implicit memory task and a simple explicit memory task, which were the simplest tasks of the study.  Sample 2 had to perform simple explicit memory tasks that were a bit more complex.  Sample 3 had the most complex tasks of the study.  After the participants performed these tasks, there were several significant findings in the results.  In sample 1 where participants performed the tasks that involved the lowest level of complexity, ecstasy users showed little or no memory deficits when compared to the non-drug using control group.  In sample 2, again there were little to no memory deficits in ecstasy users compared to the non-drug users.  However, in sample 3, memory deficits became much more apparent.  Ecstasy users’ performance did not match up with non-drug users or the cannabis users, even after repeated learning trials.  This study leads to the conclusion that memory deficits caused by use of ecstasy are more apparent in complex tasks rather than simpler tasks.

Brown, J., McKone, E., & Ward, J. (2010). Deficits of long-term memory in ecstasy users are related to cognitive complexity of the task.Psychopharmacology, 209(1), 51-67. Retrieved from EBSCOhost. doi:10.1007/s00213-009-1766-2