Patterns of simultaneous polysubstance use in Canadian rave attendees.

The aim of this study was to examine rave-related polydrug drug use and to determine if patterns of substance use were associated with previous rave attendance. One hundred and eighty-six rave attendees (50% female) representing a wide range of ages (16 to 47 years; mean=23.5, sd=5.15) and levels of rave attendance experience (1 to 400 events) completed structured interviews in Montreal, Canada between November 2002 and September 2003 about their rave attendance patterns and their use of various licit and illicit substances at the most recently attended event. On average, participants reported using 2.5 different psychoactive substances (excluding tobacco) at the most recent event attended. Cannabis, alcohol, MDMA (ecstasy), amphetamine, cocaine, ketamine, and GHB were the most frequently reported substances, and details about their orders of administration, dosages, and patterns of co-administration are presented and discussed. The total lifetime number of raves attended by participants varied considerably (mean=48.6; sd=69.7; median=25), and there was a positive correlation between the number events attended and number of substances used at the most recent event attended (p<0.001). Analyses revealed that individuals reporting the use of ketamine, GHB, and/or cocaine at the most recent event had attended significantly more events than nonusers even when controlling for various demographic variables. A subset of respondents (n=27) completed a second interview to determine the reliability of their responses. Results indicated that respondents could reliably recall details about which drugs were used, the total doses administered, as well as order of drug administration.