The illicit drug methylenedioxymethamphetamine, also called MDMA or ecstasy, is known to cause memory problems. A new study for the first time finds that extended use of the drug can exacerbate this damage.
Researchers Konstantine K. Zakzanis and Donald A. Young of the University of Toronto identified 15 ecstasy users, ages 17 to 31. None reported alcohol dependence, and all had abstained from drugs for 2 weeks before testing.
The researchers gave each person a battery of standard memory tests, then repeated them 1 year later. Aside from their 2-week abstinence, the participants had used ecstasy on average 2.4 times per month for roughly 18 months before the first tests. The volunteers continued to use the drug about that often in the year between test sessions.
To probe short-term recall, researchers showed the ecstasy users a picture of a person while saying the individual’s first and last names. After doing other tasks, the participants were asked to recall the names. Other tests included researchers reading aloud a short passage from a news story and later asking participants to recall details.
The tests revealed that most aspects of the volunteers’ memory worsened over the year, the researchers report in the April 10 Neurology. In particular, recalling a story read aloud declined significantly. Higher ecstasy intake before and between testing sessions hurt performance more, Zakzanis says.
Most participants also used other drugs, including marijuana and cocaine. While these hamper thinking, previous research has shown that ecstasy has the greatest effect on memory, he notes.
When the researchers revealed results of the second tests to the study participants, about half claimed they would quit taking the drug. Eight months later, Zakzanis has now begun asking the participants whether they are abstaining from ecstasy. He plans a third round of memory tests, which could indicate whether the apparent effects of ecstasy are permanent or wear off with abstinence.