Rationale: 3,4-Methylenedioxymethamphetamine (MDMA) mainly releases seroton
in (5-HT) and is contained in the recreational drug Ecstasy. 5-HT is known
to play an important role in mood and anxiety disorders, for which there is
a female preponderance. To date, there are no systematic data on gender di
fferences in the subjective effects of MDMA. Objectives: The present work a
nalyzed the pooled data from three controlled studies on the psychological
and physiological effects of MDMA in healthy volunteers with no or minimal
MDMA experience. A particular focus of the analyses were possible gender di
fferences. Methods: A total of 74 subjects (54 male, 20 female) participate
d in all three studies. MDMA in oral, doses ranging from 70-150 mg (1.35-1.
8 mg/kg) was administered under double-blind placebo-controlled conditions.
Subjective peak changes were assessed by standardized psychometric rating
scales. Physiological measures were blood pressure, heart rate, and periphe
ral body temperature. Adverse drug effects were assessed during the experim
ental session and after 24 h, Results: Psychoactive effects of MDMA were mo
re intense in women than in men. Women especially had higher scores for MDM
A-induced perceptual changes, thought disturbances, and fear of loss of bod
y control. The dose of MDMA positively correlated with the intensity of per
ceptual changes in women. Acute adverse effects and sequelae were also more
frequent in female than in male subjects. In contrast, men showed higher i
ncreases in blood pressure than woman. Conclusions: The fact that equal dos
es of MDMA per kilogram body weight produce stronger responses in women com
pared to men is consistent with an increased susceptibility of women to the
5-HT-releasing effects of MDMA. Our results also indicate that increasing
doses of MDMA produce more hallucinogen-like perceptual alterations, partic
ularly in women.