A preliminary evaluation of a web-based intervention for college marijuana use.

Young adults in college have high rates of marijuana use, abuse, and dependence. Web-based interventions are increasingly popular, but their dissemination exceeds empirical support. One popular but understudied program is The Marijuana eCHECKUP TO GO (e-TOKE) for Universities & Colleges (San Diego State University Research Foundation, 2009). The aim of the present study was to evaluate its short-term effectiveness in changing marijuana involvement and perceived norms in undergraduates. Participants were 317 undergraduates (52% female, 78% White) who reported marijuana use within the month preceding baseline; each was randomly assigned to 1 of 4 conditions formed by crossing e-TOKE versus assessment only, with brief versus extensive baseline assessment (to assess assessment reactivity). Thus, 161 (51%) received eTOKE (77 with extended baseline, 84 with brief baseline), and 156 (49%) received assessment-only control (85 with extended baseline, 71 with brief baseline). 1 month later, all participants reported on marijuana use, problems, abuse and dependence symptoms, and norms. Assessment reactivity analyses yielded no significant differences by assessment condition. Individuals completing the e-TOKE program reported less extreme descriptive norms (ps < 0.01) but no decrease in marijuana use frequency, problems, abuse or dependence symptoms, or changes in injunctive norms (ps > 0.10). Thus, e-TOKE reduces perceptions of others' use, but this study did not provide evidence for its utility in changing personal use and problem indicators in the short-term. More research with longer follow-ups is indicated, given the possibility that descriptive norms could mediate behavior change.