Emerging psychoactive substance use among regular ecstasy users in Australia.

Background: The past decade has seen the development of an array of emerging psychoactive substances (EPS), however, there is minimal information on the extent of their use outside Europe. This study aimed to determine the extent of use of EPS from stimulant (such as mephedrone) and psychedelic classes (such as 5-methoxy-dimethyltryptamine [5-MeO-DMT]) among an Australian sample of regular ecstasy users (REU). Further, to determine if consumers of these drugs represent a distinct subgroup of REU.

Methods: Australian national cross-sectional surveys of 693 regular (at least monthly) ecstasy users conducted during 2010.

Results: More than one quarter (28%) of REU had used an EPS in the past six months, most commonly from the stimulant class (20%, typically mephedrone, 17%) rather than the psychedelic class (13%). Demographics and risk behaviours of REU that used stimulant EPS were largely no different from non-EPS consuming REU. Those using psychedelic EPS were distinct, initiating ecstasy use earlier, more frequently using multiple substances (cannabis, inhalants, GHB, ketamine) and more commonly experiencing legal, psychological and social problems.

Conclusions: Psychedelic EPS use appears largely restricted to a distinct subset of REU with high-level non-injecting polydrug use, but use appears generally limited. The demographic similarity of stimulant EPS consumers with 'mainstream' REU, in conjunction with positive responses to the psychoactive effects of these drugs and declining ecstasy purity, suggests strong potential for stimulant EPS to expand further into ecstasy markets. Such drugs may have a greater public health impact than ecstasy, and merit careful monitoring into the future.