title: Variations in Cannabis Use Level and Correlates in Opiate-Users on Methadone Maintenance Treatment: A French Prospective Study.
abstract: BACKGROUND
  Concurrent cannabis use is very frequent among opioid users on methadone maintenance treatment (MMT), which could reflect a coping strategy during MMT. The aims of this study were to describe variations in cannabis use and to explore whether MMT could modify the patterns of cannabis use correlates.
  
  
  METHODS
  The sample included 188 opioid-dependent individuals who initiated MMT and were prospectively followed for 12 months. Cannabis use was monitored at enrollment and at months 3, 6 and 12. The relationships between cannabis use level (non-daily use and daily use vs. no use in the previous month) and its determinants (socioeconomic factors, substance use characteristics and mental health) were explored using mixed multinomial logistic regressions.
  
  
  RESULTS
  No significant variation trend in cannabis use levels was observed during the follow-up period among the 188 subjects analyzed (p=0.85). After adjustment for socio-demographic factors, opioid use was associated with both non-daily (OR=3.11, p=0.01) and daily cannabis use (OR=2.58, p=0.04). Moreover the number of health problems reported was associated with daily cannabis use (OR=1.12 per 1-problem increase, p=0.004). The factors associated with cannabis use appeared similar before and after starting treatment (no significant interaction observed between MMT and any factor).
  
  
  CONCLUSIONS
  Cannabis use during MMT more likely reflects pre-existing common liability to substance use or self-medication practices towards health problems than a behavior aimed at managing problems with MMT. With recent research suggesting an interaction between cannabinoid and opioid systems, the benefit of cannabis-based pharmacotherapies during MMT should be further explored in addiction research.
authors.affiliation: Centre d'épidémiologie et de santé publique des armées, Marseille, France; INSERM, UMR912 (SESSTIM), 13006, Marseille, France. Electronic address: aurelie_marie@hotmail.fr.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Mayet
authors.affiliation: INSERM, UMR912 (SESSTIM), 13006, Marseille, France; Aix Marseille Université, UMR_S912, IRD, 13006, Marseille, France; ORS PACA, Observatoire Régional de la Santé Provence-Alpes-Côte d'Azur, 13006, Marseille, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Lions
authors.affiliation: INSERM, UMR912 (SESSTIM), 13006, Marseille, France; Aix Marseille Université, UMR_S912, IRD, 13006, Marseille, France; ORS PACA, Observatoire Régional de la Santé Provence-Alpes-Côte d'Azur, 13006, Marseille, France.
authors.forename: Perrine
authors.initials: P
authors.lastname: Roux
authors.affiliation: INSERM, UMR912 (SESSTIM), 13006, Marseille, France; Aix Marseille Université, UMR_S912, IRD, 13006, Marseille, France; ORS PACA, Observatoire Régional de la Santé Provence-Alpes-Côte d'Azur, 13006, Marseille, France.
authors.forename: Marion
authors.initials: M
authors.lastname: Mora
authors.affiliation: INSERM, UMR912 (SESSTIM), 13006, Marseille, France; Aix Marseille Université, UMR_S912, IRD, 13006, Marseille, France; ORS PACA, Observatoire Régional de la Santé Provence-Alpes-Côte d'Azur, 13006, Marseille, France.
authors.forename: Gwenaelle
authors.initials: G
authors.lastname: Maradan
authors.affiliation: Oppelia, Paris, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Morel
authors.affiliation: Centre Pierre Nicole, Paris, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Michel
authors.affiliation: Centre d'épidémiologie et de santé publique des armées, Marseille, France; INSERM, UMR912 (SESSTIM), 13006, Marseille, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Marimoutou
authors.affiliation: INSERM, UMR912 (SESSTIM), 13006, Marseille, France; Aix Marseille Université, UMR_S912, IRD, 13006, Marseille, France; ORS PACA, Observatoire Régional de la Santé Provence-Alpes-Côte d'Azur, 13006, Marseille, France.
authors.forename: Maria Patrizia
authors.initials: MP
authors.lastname: Carrieri
mesh_terms: D000223:Adaptation, Psychological; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008385:Marijuana Smoking / Q000523:psychology*; D008691:Methadone / Q000627:therapeutic use*; D009294:Narcotics / Q000627:therapeutic use*; D058850:Opiate Substitution Treatment / Q000523:psychology*; D009293:Opioid-Related Disorders / Q000188:drug therapy* / Q000523:psychology
chemical_list: D009294:Narcotics; D008691:Methadone
keywords: Cannabis; Common liability; Methadone maintenance treatment; Opioids; Withdrawal