Abstract
INTRODUCTION: 3,4-methylenedioxymethamphetamine (MDMA) is known to improve psychomotor function and mood when measured during daytime. However, MDMA users tend to take this drug at dance parties while staying awake for prolonged periods of time. SUBJECTS AND METHODS: This study was designed to assess dose-related residual effects of MDMA on psychomotor function and mood after a night without sleep. Sixteen recreational MDMA users received single doses of 25, 50, and 100 mg MDMA in a randomized, double-blind, placebo-controlled cross-over study. RESULTS: Results showed that sleep loss significantly impaired psychomotor function. MDMA generally did not affect performance but did improve rapid information processing at the highest dose in the morning after administration. In the evening, MDMA also increased subjective ratings of positive mood at every dose and subjective arousal at the highest dose. These subjective effects were no longer present after a night of sleep loss. DISCUSSION: It is concluded that sleep deprivation impairs psychomotor function and that stimulant effects of MDMA are not sufficient to compensate for this impairment.