Predicting future anabolic-androgenic steroid use intentions with current substance use: findings from an internet-based survey.

Objective: To explore how current substance use, including the use of sports supplements and illicit drugs, may impact upon a person's future intentions to use anabolic-androgenic steroids (AAS).

Design: Web-based survey.

Participants: Two hundred fourteen exercising males (mean age, 30 years; range, 17-61 years) recruited from 5 gymnasia in Sydney, Australia, completed a web-based survey. The survey contained questions relating to sport supplement use, illicit substance use, reasons for currently not using AAS, and reasons for intending to use AAS in the future.

Interventions: Participants completed a structured interview schedule that included questions regarding licit and illicit substance use, reasons for non-AAS use, and, where appropriate, reasons for intended future AAS use.

Main Outcome Measures: The planned main outcome measure was positive intention to use AAS.

Results: Sixteen percent of the sample indicated that they would use AAS in the future. Reasons for future AAS use included increasing muscle size (80%), improving appearance (74%), and increasing strength (57%). Four-fifths (80%) of the sample reported use of sports supplements, with vitamins and protein supplements commonly reported (83% and 67%, respectively); more than one-third (36%) reported use of creatine in the past 6 months. Half (52%) of the sample reported use of illicit substances in the preceding 6 months, with amphetamines and cannabis commonly reported (66% and 62%, respectively). Significant predictors of intending to use AAS included past 6-month use of creatine and knowing AAS users.

Conclusions: The use of sport supplements and/or illicit substances may remove barriers for the future use of such drugs as AAS. Future research is necessary to explore in depth whether such substances may act as a "gateway" to future AAS use.