title: Approach to cannabis use disorder in primary care: focus on youth and other high-risk users.
abstract: OBJECTIVE
  To review the clinical features and complications of at-risk cannabis use and cannabis use disorder, and to outline an office-based protocol for screening, identifying, and managing this disorder.
  
  
  METHODS
  PubMed was searched for controlled trials, observational studies, and reviews on cannabis use among adolescents and young adults; cannabis-related medical and psychiatric harms; cannabis use disorder and its treatment; and lower-risk cannabis use guidelines.
  
  
  RESULTS
  Physicians should ask all patients about cannabis use. They should ask adolescents and young adults and those at highest risk of cannabis-related harms (those with concurrent psychiatric or substance use disorders) more frequently. Physicians should also ask about cannabis use in patients who have problems that could be caused by cannabis, such as mood disorders, psychosis, and respiratory symptoms. In patients who report cannabis use, physicians should inquire about frequency and amount, tolerance and withdrawal symptoms, attempts to reduce use, and cannabis-related harms. Lower-risk cannabis users smoke, inhale, or ingest cannabis occasionally without evidence of school, work, or social dysfunction; those with problematic use often use cannabis daily or almost daily, have difficulty reducing their use, and have impaired school, work, or social functioning. Physicians should offer all patients with problematic use brief advice and counseling, focusing on the health effects of cannabis and setting a goal of abstinence (some higher-risk groups should not use cannabis at all) or reduced use, and they should provide practical strategies to reduce cannabis use. Physicians should incorporate simple motivational interviewing techniques into the counseling sessions. They should refer those patients who are unable to reduce use or who are experiencing harms from cannabis use to specialized care, while ensuring those patients remain connected to primary care. As well, physicians should give information on lower-risk cannabis use to all cannabis users.
  
  
  CONCLUSIONS
  Physicians should screen all patients in their practices at least once for cannabis use, especially those who have problems that might be caused by cannabis. Physicians should screen those at higher risk more often, at least annually. Lower-risk cannabis use should be distinguished from problematic use. Brief counseling should be provided to those with problematic use; these patients should be referred to specialists if they are unable to reduce or cease use.
authors.affiliation: Physician and addiction medicine physician in the Department of Family and Community Medicine and the Addiction Medicine Service at St Michael's Hospital in Toronto, Ont. TurnerSu@smh.ca.
authors.forename: Suzanne D
authors.initials: SD
authors.lastname: Turner
authors.affiliation: Physician and addiction medicine physician in the Department of Family Medicine and the Substance Use Service at Women's College Hospital in Toronto.
authors.forename: Sheryl
authors.initials: S
authors.lastname: Spithoff
authors.affiliation: Medical Director of the Substance Use Service at Women's College Hospital.
authors.forename: Meldon
authors.initials: M
authors.lastname: Kahan
mesh_terms: D000293:Adolescent; D000328:Adult; D002170:Canada; D017831:Diagnosis, Dual (Psychiatry); D006801:Humans; D002189:Marijuana Abuse / Q000175:diagnosis / Q000517:prevention & control; D008403:Mass Screening / Q000379:methods / Q000458:organization & administration; D001523:Mental Disorders / Q000175:diagnosis*; D062405:Motivational Interviewing; D017410:Practice Guidelines as Topic; D011320:Primary Health Care / Q000379:methods*; D012572:School Health Services