The relationship between cannabis outcome expectancies and cannabis refusal self-efficacy in a treatment population.

BACKGROUND AND AIMS Self-efficacy beliefs and outcome expectancies are central to Social Cognitive Theory (SCT). Alcohol studies demonstrate the theoretical and clinical utility of applying both SCT constructs. This study examined the relationship between refusal self-efficacy and outcome expectancies in a sample of cannabis users, and tested formal mediational models. DESIGN Patients referred for cannabis treatment completed a comprehensive clinical assessment, including recently validated cannabis expectancy and refusal self-efficacy scales. SETTING A hospital alcohol and drug out-patient clinic. PARTICIPANTS Patients referred for a cannabis treatment [n = 1115, mean age 26.29, standard deviation (SD) 9.39]. MEASUREMENTS The Cannabis Expectancy Questionnaire (CEQ) and Cannabis Refusal Self-Efficacy Questionnaire (CRSEQ) were completed, along with measures of cannabis severity [Severity of Dependence Scale (SDS)] and cannabis consumption. FINDINGS Positive (β = -0.29, P < 0.001) and negative (β = -0.19, P < 0.001) cannabis outcome expectancies were associated significantly with refusal self-efficacy. Refusal self-efficacy, in turn, fully mediated the association between negative expectancy and weekly consumption [95% confidence interval (CI) = 0.03, 0.17] and partially mediated the effect of positive expectancy on weekly consumption (95% CI = 0.06, 0.17). CONCLUSIONS Consistent with Social Cognitive Theory, refusal self-efficacy (a person's belief that he or she can abstain from cannabis use) mediates part of the association between cannabis outcome expectancies (perceived consequences of cannabis use) and cannabis use.