The 'party drug' Ecstasy does affect the memory of people who take it, especially in high-pressure situations, according to a new study by an ANU Clinical Psychology PhD student.
Mr John Brown, from the School of Psychology at ANU, will present the findings of his four-year study at the Australian Psychological Society conference in Sydney.
The study is the first in Australia to examine the effects of Ecstasy on memory using advanced cognitive psychology research techniques. While there is a growing body of evidence regarding the neurotoxic effects of Ecstasy, commonly used memory tests have often failed to reveal reliable memory deficits in Ecstasy users.
The research compared the average memory performance of three groups of about 30 participants: Ecstasy users who had not used any drug for two weeks; drug users who do not use Ecstasy (mainly marijuana users); and those who do not use illicit drugs.
“Using standard clinical neuropsychological tests, we identified small deficits in the average memory performance of Ecstasy users compared to both of the other groups,” Mr Brown says.
“However, a new test developed as part of this research project revealed relatively large memory deficits that appeared to be due to problems processing information at the time it is being stored, rather than failures in holding information in memory or to retrieving it later on.”
A set of 10 triplets of unrelated words (for example: Dingo - Spanner – Muffin) were quickly read aloud to the participants with only about one second between each triplet. The participants then had to recall as many of the triplets as they could.
Under these demanding conditions, the results were significant enough to suggest that Ecstasy users may experience functional deficits in demanding situations in real-life.
“There are a number of factors that could contribute to the observed effects,” Mr Brown says. “But we have been able to rule out age, sex, level of education, estimated IQ, current and past mental health and alcohol as causes of the deficits.
“Marijuana has some effect, but only accounts for a portion of the deficit. In particular, the average rate at which Ecstasy users learnt new information under difficult conditions was significantly lower than that of marijuana users.”
According to Mr Brown, much larger studies will be required to more fully investigate the effects of stimulants such as methamphetamines, “but it appears from this research that Ecstasy is a principal cause of the memory deficits”.
Mr Brown will present his findings at the Australian Psychological Society conference at 9am, Saturday, 2 October 2004.