Long-term effects of MDMA (Ecstasy) on the human central nervous system revealed by visual evoked potentials

Abstract

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.

Electrophysiological evidence of atypical processing underlying mental set shifting in ecstasy polydrug and polydrug users.

“…Longer latencies and smaller amplitude of the P3 response are indicative of cognitive impairment. Diminished P3 potentials have been observed in heavy and moderate ecstasy user groups in simple discrimination tasks (Casco et al 2005) . Gamma et al (2005) report observable reductions in the P3 amplitudes of ecstasy users in a Go/No-go task compared to controls, though this could be a polydrug effect.…”

The Effect of Catecholamine Depletion by Alpha-Methyl-Para-Tyrosine on Measures of Cognitive Performance and Sleep in Abstinent MDMA Users

“…Other clinical and physiological abnormalities that have been reported in MDMA users include impulsivity (Morgan et al, 2006;Quednow et al, 2007), neuroendocrine dysfunction (Gerra et al, 1998(Gerra et al, , 2000(Gerra et al, , 2003McCann et al, 2000;Verkes et al, 2001), alterations in pain modulation (O'Regan and Clow, 2004), sleep architecture (Allen et al, 1993;Ricaurte and McCann, 2001), visual-evoked potentials (Casco et al, 2005), and event-related potentials (Mejias et al, 2005). Like cognitive function, all of these behavioral spheres are known to be influenced, in part, by brain 5-HT systems.…”

ERP evidence suggests executive dysfunction in ecstasy polydrug users

“…A diminished P3 potential is understood to reflect cognitive dysfunction. Casco et al (2005) observed a diminished P3 response in a simple discrimination task in moderate and heavy ecstasy users compared to controls in a visually evoked potential study. Furthermore Gamma et al (2005) report reductions in the P3 amplitudes of ecstasy users, compared to controls in an inhibitory control (Go-Nogo) task.…”