Evidence of increased activation underlying cognitive control in ecstasy and cannabis users

Abstract

Evidence suggests that users of ecstasy (3,4-methylenedioxymethamphetamine) have behavioural and cognitive deficits and show increased impulsivity. Impulse control impairments have been shown to be common to a number of addictive behaviours and may constitute a risk factor for drug abuse and dependence. The aim of this study was to investigate brain activation during response inhibition and performance monitoring in current recreational drug users who predominantely used ecstasy. Twenty drug users (ten female) and twenty healthy controls were scanned during performance of a response inhibition GO/NOGO task using functional magnetic resonance imaging. No performance deficits were evident. However, the drug user group revealed elevated frontal and parietal BOLD response during successful inhibitions, and temporal, frontal, and cingulate hyperactivity during commision errors. In addition, the users showed reduced deactivation in the default-mode network during task performance. Whether contributing to or arising from drug use, these results reveal dysregulation in brain regions subserving cognitive control and default mode processes in current recreational drug users mirroring effects previously observed for "harder" drugs of abuse.