Long-term effects of MDMA (Ecstasy) on the human central nervous system revealed by visual evoked potentials.
Several studies indicate long-term cognitive impairment of MDMA (ecstasy) users. In the present study we attempted to establish whether electrophysiological correlates of low-level cognitive processes present a long-term alteration, dependent on the level of use of ecstasy. We addressed this issue by investigating amplitude and latency of VEPs related to a very simple discrimination task involving sustained attention (arousal). Eight heavy-MDMA users, eight moderate-MDMA users and 18 drug-free control subjects were asked to discriminate whether the digit at the centre of the screen was 1 or 2. None of the subjects (except one) had used MDMA in the 6 months previous testing. We measured psychophysical performance and EEG, recorded in Oz and Fz during task execution. The heavy-MDMA users made significantly more errors than the other two groups (p < .05). Moreover, they presented reduced amplitude but not latency of VEPs in both Oz and Fz. The effect in Oz is present in P200 (for heavy users only, p < .05) and in P300 components (for both MDMA groups; heavy users: p < .001, moderate users: p < .0.5). In Fz, the amplitude effect is present in N250 (for heavy users only, p < .05) and in P300 components (for both MDMA groups; heavy users: p < .05, moderate users: p < .05). The three groups do not differ in early components, reflecting low-level processing. These results provide evidence of long-term electrophysiological abnormality displayed by ecstasy users and agree with the suggestion that even typical recreational doses of ecstasy are sufficient to cause long-term altered cortical activity in humans.
Casco
C
C
Dipartimento di Psicologia Generale, Universita' di Padova, Italy. clara.casco@unipd.it
Forcella
Mc
M
Beretta
G
G
Grieco
A
A
Campana
G
G
D000328:Adult; D019969:Amphetamine-Related Disorders / Q000503:physiopathology*; D002490:Central Nervous System / Q000187:drug effects* / Q000503:physiopathology; D003072:Cognition Disorders / Q000139:chemically induced / Q000175:diagnosis; D004569:Electroencephalography; D018913:Event-Related Potentials, P300 / Q000502:physiology; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006213:Hallucinogens / Q000009:adverse effects*; D006801:Humans; D008297:Male; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000009:adverse effects*; D009483:Neuropsychological Tests; D013995:Time
D006213:Hallucinogens; D018817:N-Methyl-3,4-methylenedioxyamphetamine