The effects of cannabis use expectancies on self-initiated cannabis cessation

Authors

  • Matthew Tyler Boden,

    Corresponding author
    • Center for Innovation to Implementation, VA Palo Alto Health Care System, Menlo Park, CA, USA
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  • James R. McKay,

    1. Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA
    2. Center of Excellence in Substance Abuse Treatment and Education, Philadelphia VAMC, Philadelphia, PA, USA
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  • W. Robert Long,

    1. Centre for Epidemiology and Biostatistics, University of Leeds, Leeds, UK
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  • Marcel O. Bonn-Miller

    1. Center for Innovation to Implementation, VA Palo Alto Health Care System, Menlo Park, CA, USA
    2. Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA
    3. Center of Excellence in Substance Abuse Treatment and Education, Philadelphia VAMC, Philadelphia, PA, USA
    4. National Center for PTSD, VA Palo Alto Health Care System, Menlo Park, CA, USA
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Correspondence to: Matthew Boden, Center for Innovation to Implementation, VA Palo Alto Health Care System, 795 Willow Road (152-MPD), Menlo Park, CA 94025, USA. E-mail: Matthew.Boden@va.gov

Abstract

Aims

To prospectively investigate the relation between cannabis use expectancies and cannabis use prior to and during a self-initiated cannabis cessation attempt.

Design

Cohort design that followed participants for 4 weeks following a self-initiated cessation attempt.

Setting

United States Department of Veterans Affairs medical center.

Participants

One hundred cannabis dependent military veterans.

Measurements

The Marijuana Effects Expectancy Questionnaire at baseline; the timeline follow-back procedure at baseline and during the cessation attempt.

Findings

Cannabis use at baseline was associated with positive (P = 0.01), but not negative (P = 0.25), expectancies. Cannabis lapse was associated with positive (P = 0.03) and negative expectancies (P = 0.01), and relapse was associated with positive (P = 0.04), but not negative (P = 0.21), expectancies. The trajectory of average cannabis use during the cessation period was associated with positive (P = 0.03), but not negative (P = 0.96), expectancies. Results were similar in effect and statistical significance when adjusting for demographic factors, motivation to quit cannabis, mental disorder diagnoses, and alcohol and tobacco use, and when analyzing complete data sets obtained through multiple imputation.

Conclusions

In the USA, cannabis use expectancies, especially those regarding the positive effects of cannabis use, appear to be strongly and consistently linked to cannabis use and quit failure.

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