The use of methylenedioxymethamphetamine (MDMA), better known as the club drug ecstasy, does not appear to cause any long-term increases in aggressive behavior, according to research published in Experimental and Clinical Psychopharmacology.
Previous research found signs of increased aggressiveness three to four days after the use of the ecstasy, but whether this was a short-term effect or could have long-term consequences remained uncertain.
To better understand the effects of ecstasy, a team of scientists from London investigated whether recreational users of ecstasy showed increased self-rating of aggression or increased aggressive interpretive bias.
Aggressive interpretive bias is a type of cognitive bias that refers to misinterpreting ambiguous information as threatening or hostile.
Along with being compared to non-users, current recreational users of ecstasy were also compared to the users of other recreational drugs and former users of ecstasy.
For example, the sentence, “The painter drew the knife,” could be interpreted as either the painter drawing a picture of a knife or the painter brandishing a knife. Aggressive interpretive bias refers to the tendency to interpret this type of ambiguous sentence in an aggressive way.
“The study found no evidence that either current or ex-ecstasy users have an aggressive interpretive bias,” according to the authors of the study.
“Intriguingly, these findings support the idea that the increased cognitive aggressive bias and increased self-rated aggression found in ecstasy users four days following use of the drug is a transient phenomenon, as the current users, who had not taken ecstasy for an average of approximately two weeks and a minimum of six days, did not show increased aggression.”
The transient effect of ecstasy on aggression appears to be due to the drug’s effect on serotonin receptors.
Reference:
Hoshi, R., Cohen, L., Lemanski, L., Piccini, P., Bond, A. & Curran, H.V. (2007). Ecstacy (MDMA) does not have long-term effects on aggressive interpretative bias: a study comparing current and ex-ecstasy users with poly drug and drug-naive controls. Experimental and Clinical Psychopharmacology, Vol. 15, No. 4: 351-358.