Believing Cannabis Has Positive Effects Predicted Failure to Quit in Veterans

Positive expectations about cannabis effects, such as believing it relieves tension or enhances social experiences, consistently predicted cannabis use, lapse, and relapse during a 4-week quit attempt among 100 veterans.

Boden, Matthew Tyler et al.·Addiction (Abingdon·2013·Moderate EvidenceLongitudinal Cohort

Quitting (221)Addiction (1380)

Quick Facts

Study Type

Longitudinal Cohort

Evidence

Moderate Evidence

Sample

N=100

What This Study Found

One hundred cannabis-dependent military veterans were followed during a self-initiated 4-week quit attempt. Positive cannabis expectancies (believing cannabis produces desirable effects) predicted multiple outcomes: higher baseline use, lapsing during the attempt, relapsing fully, and the overall trajectory of use during cessation.

Negative expectancies (believing cannabis has bad effects) played a limited role, predicting only initial lapse but not sustained use or relapse. Results held after adjusting for demographics, motivation to quit, mental health diagnoses, and alcohol and tobacco use.

Key Numbers

100 veterans followed 4 weeks. Positive expectancies predicted: baseline use (p=0.01), lapse (p=0.03), relapse (p=0.04), use trajectory (p=0.03). Negative expectancies predicted only lapse (p=0.01). Results robust after covariate adjustment.

How They Did This

Cohort design following 100 cannabis-dependent military veterans for 4 weeks after a self-initiated quit attempt. Cannabis use expectancies measured at baseline with the Marijuana Effects Expectancy Questionnaire. Cannabis use tracked with Timeline Followback at baseline and during cessation. Analyses adjusted for multiple covariates.

Why This Research Matters

Understanding what predicts quit failure helps design better interventions. If positive expectancies, specific beliefs about cannabis benefits, drive continued use, then therapeutically challenging these beliefs could improve outcomes. Simply knowing cannabis is harmful (negative expectancies) was not enough to prevent relapse.

The Bigger Picture

This finding parallels alcohol research showing that positive outcome expectancies are stronger predictors of drinking behavior than negative ones. It suggests that cannabis cessation interventions should focus more on challenging positive beliefs about cannabis than on emphasizing negative consequences.

What This Study Doesn't Tell Us

Self-guided quit attempts may not represent structured treatment settings. Military veterans may not be representative of all cannabis users. Four-week follow-up is relatively short. Expectancies were measured at baseline and may change during the quit attempt. Self-report measures for both expectancies and use.

Questions This Raises

?Would cognitive restructuring of positive cannabis expectancies improve quit rates?
?Do expectancies change during treatment, and does that change predict outcomes?
?Are positive expectancies about specific effects (tension relief, social enhancement) differentially predictive?

Trust & Context

Key Stat:: Positive expectancies predicted lapse, relapse, and use trajectory during quit attempts
Evidence Grade:: Prospective cohort study with multiple outcome measures and appropriate controls; moderate evidence.
Study Age:: Published in 2013. Expectancy-based interventions for substance use have continued to develop.
Original Title:: The effects of cannabis use expectancies on self-initiated cannabis cessation.
Published In:: Addiction (Abingdon, England), 108(9), 1649-57 (2013)
Authors:: Boden, Matthew Tyler(4), McKay, James R, Long, W Robert(2), Bonn-Miller, Marcel O
Database ID:: RTHC-00654

Evidence Hierarchy

Meta-Analysis / Systematic Review

Randomized Controlled Trial

Cohort / Case-ControlFollows or compares groups over time

This study

Cross-Sectional / Observational

Case Report / Animal Study

Follows a group of people over time to track how outcomes develop.

What do these levels mean? →

Frequently Asked Questions

Why do positive beliefs about cannabis matter more than knowing it is harmful?

People are generally more motivated by anticipated rewards than by anticipated costs. A veteran who believes cannabis helps with relaxation, sleep, or social connection has a strong pull toward use, even if they also know it has negative consequences. Addressing these positive beliefs directly may be more effective than emphasizing risks.

What are cannabis use expectancies?

Expectancies are beliefs about what cannabis will do for you. Positive expectancies include things like "cannabis helps me relax," "cannabis makes socializing easier," or "cannabis enhances pleasure." Negative expectancies include beliefs that cannabis impairs performance or causes health problems. This study found positive expectancies were stronger predictors of continued use.

Cite This Study

RTHC-00654·https://rethinkthc.com/research/RTHC-00654

APA

Boden, Matthew Tyler; McKay, James R; Long, W Robert; Bonn-Miller, Marcel O. (2013). The effects of cannabis use expectancies on self-initiated cannabis cessation.. Addiction (Abingdon, England), 108(9), 1649-57. https://doi.org/10.1111/add.12233

MLA

Boden, Matthew Tyler, et al. "The effects of cannabis use expectancies on self-initiated cannabis cessation.." Addiction (Abingdon, 2013. https://doi.org/10.1111/add.12233

RethinkTHC

RethinkTHC Research Database. "The effects of cannabis use expectancies on self-initiated c..." RTHC-00654. Retrieved from https://rethinkthc.com/research/boden-2013-the-effects-of-cannabis

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Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.

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