The acute effects of 3,4-methylenedioxymethamphetamine and d-methamphetamine on human cognitive functioning.
BACKGROUND
This study investigated the acute (3-h) and 24-h post-dose cognitive effects of oral 3,4-methylenedioxymethamphetamine (MDMA), d-methamphetamine, and placebo in a within-subject double-blind laboratory-based study in order to compare the effect of these two commonly used illicit drugs on a large number of recreational drug users.


METHODS
Sixty-one abstinent recreational users of illicit drugs comprised the participant sample, with 33 females and 28 males, mean age 25.45 years. The three testing sessions involved oral consumption of 100 mg MDMA, 0.42 mg/kg d-methamphetamine, or a matching placebo. The drug administration was counter-balanced, double-blind, and medically supervised. Cognitive performance was assessed during drug peak (3 h) and at 24 h post-dosing time-points. Blood samples were also taken to quantify the levels of drug present at the cognitive testing time-points.


RESULTS
Blood concentrations of both methamphetamine and MDMA at drug peak samples were consistent with levels observed in previous studies. The major findings concern poorer performance in the MDMA condition at peak concentration for the trail-making measures and an index of working memory (trend level), and more accurate performance on a choice reaction task within the methamphetamine condition. Most of the differences in performance between the MDMA, methamphetamine, and placebo treatments diminished by the 24-h testing time-point, although some performance improvements subsisted for choice reaction time for the methamphetamine condition.


CONCLUSIONS
Further research into the acute effects of amphetamine preparations is necessary to further quantify the acute disruption of aspects of human functioning crucial to complex activities such as attention, selective memory, and psychomotor performance.
Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia. cstough@gmail.com
Con
C
Stough
Rebecca
R
King
Katherine
K
Papafotiou
Phillip
P
Swann
Edward
E
Ogden
Keith
K
Wesnes
Luke A
LA
Downey
D000328:Adult; D003071:Cognition / Q000187:drug effects* / Q000502:physiology*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008694:Methamphetamine / Q000008:administration & dosage*; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000008:administration & dosage*; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000187:drug effects / Q000502:physiology; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D013997:Time Factors; D055815:Young Adult
D008694:Methamphetamine; D018817:N-Methyl-3,4-methylenedioxyamphetamine