title: Intentional cannabis use to reduce crack cocaine use in a Canadian setting: A longitudinal analysis.
abstract: No effective pharmacotherapies exist for the treatment of crack cocaine use disorders. Emerging data suggests that cannabinoids may play a role in reducing cocaine-related craving symptoms. This study investigated the intentional use of cannabis to reduce crack use among people who use illicit drugs (PWUD).
  
  
  
  Data were drawn from three prospective cohorts of PWUD in Vancouver, Canada. Using data from participants reporting intentional cannabis use to control crack use, we used generalized linear mixed-effects modeling to estimate the independent effect of three pre-defined intentional cannabis use periods (i.e., before, during and after first reported intentional use to reduce crack use) on frequency of crack use.
  
  
  
  Between 2012 and 2015, 122 participants reported using cannabis to reduce crack use, contributing a total of 620 observations. In adjusted analyses, compared to before periods, after periods were associated with reduced frequency of crack use (Adjusted Odds Ratio [AOR]=1.89, 95% Confidence Interval [CI]: 1.02-3.45), but not the intentional use periods (AOR=0.85, 95% CI: 0.51-1.41). Frequency of cannabis use in after periods was higher than in before periods (AOR=4.72, 95% CI: 2.47-8.99), and showed a tendency to lower frequency than in intentional cannabis use periods (AOR=0.56, 95% CI: 0.32-1.01).
  
  
  
  A period of intentional cannabis use to reduce crack use was associated with decreased frequency of crack use in subsequent periods among PWUD. Further clinical research to assess the potential of cannabinoids for the treatment of crack use disorders is warranted.
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada; Department of Medicine, University of British Columbia, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada.
authors.forename: M Eugenia
authors.initials: ME
authors.lastname: Socías
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada; Department of Medicine, University of British Columbia, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kerr
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada; Department of Medicine, University of British Columbia, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada.
authors.forename: Evan
authors.initials: E
authors.lastname: Wood
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada.
authors.forename: Huiru
authors.initials: H
authors.lastname: Dong
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Lake
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada; Department of Medicine, University of British Columbia, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada.
authors.forename: Kanna
authors.initials: K
authors.lastname: Hayashi
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada; School of Public Policy, Simon Fraser University, 515 West Hastings Street - Suite 3271, Vancouver, BC V6B 5K3, Canada.
authors.forename: Kora
authors.initials: K
authors.lastname: DeBeck
authors.affiliation: Research Center, Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Rue Saint-Denis, Montréal, QC, H2X 0A9, Canada; Department of Psychiatry, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, QC H3C 3J7, Canada.
authors.forename: Didier
authors.initials: D
authors.lastname: Jutras-Aswad
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada; Department of Medicine, University of British Columbia, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada.
authors.forename: Julio
authors.initials: J
authors.lastname: Montaner
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada; Department of Medicine, University of British Columbia, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada. Electronic address: uhri-mjsm@cfenet.ubc.ca.
authors.forename: M-J
authors.initials: MJ
authors.lastname: Milloy
mesh_terms: D000328:Adult; D001955:British Columbia; D019970:Cocaine-Related Disorders / Q000534:rehabilitation*; D016578:Crack Cocaine; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D064086:Medical Marijuana / Q000627:therapeutic use*; D008875:Middle Aged; D011446:Prospective Studies; D012648:Self Care; D057566:Self Report
chemical_list: D016578:Crack Cocaine; D064086:Medical Marijuana
keywords: Cannabidiol; Cannabinoids; Cannabis; Crack cocaine; People who use drugs; Δ9-tetrahydrocannabinol