Twenty recreational drug users were asked to describe the psychological and physiological effects they experienced under MDMA (3,4-methylenedioxymethamphetamine). The subjects comprised 11 males and nine females, in the age range 18-31 years. Five subjects had taken MDMA once, nine had taken it 2-9 times, while six subjects had taken it + 10 times. Each subject completed a modified Profile of Mood States Questionnaire (POMS), an Ecstasy Effect Questionnaire, and a structured interview, covering past experience with MDMA. Increased feelings of elation, agreeableness, energy, and mental confusion were reported on-drug ( p < 0.001), together with faster heart rate, feeling hot, increased sweating and dehydration, dilated pupils, and tight jaw (trismus). Coming off-Ecstasy led to feelings of lethargy, moodiness, insomnia, depression, irritability, and paranoia. Bad MDMA trips were reported by
25 per cent of the sample, following a variety of unpleasant experiences. Chronic pharmacodynamic tolerance was not apparent, since although regular users all described their first MDMA experience as `the most intense', later trips were affected by knowledge and expectancy, rather than any diminution in drug response. Acute pharmacodynamic tolerance was, however, evident, with a period between drugs being described as necessary in order to maintain drug effectiveness. This may help explain the low addiction potential of MDMA.