title: Cannabis withdrawal in chronic cannabis users with schizophrenia.
abstract: BACKGROUND
  Chronic users of cannabis often report withdrawal symptoms after abstinence from use, but little is known about cannabis withdrawal in people with schizophrenia.
  
  
  METHODS
  Cannabis use patterns and withdrawal symptoms in adults with schizophrenia who had at least weekly cannabis use before attempting to quit without formal treatment were assessed with the Marijuana Quit Questionnaire (MJQQ), a 176-item, semi-structured questionnaire.
  
  
  RESULTS
  120 participants, predominantly African-American (62.5%) and male (76.7%), met inclusion criteria. 20.1% reported that their first regular cannabis use (median age 15 years [range 8-48]) preceded their age at first psychotic symptoms (20 [4-50] years). Twenty (16.7%) participants met lifetime criteria for cannabis abuse; 98 (81.7%) met surrogate criteria for lifetime cannabis dependence. Withdrawal symptoms were reported by 113 (94.2%) participants, with 74.2% reporting ≥4 symptoms. The most frequently reported withdrawal symptoms were craving for cannabis (59.2%), feeling anxious (52.57%), feeling bored (47.5%), feeling sad or depressed (45.8%), feeling irritable or jumpy (45.0%), feeling restless (43.3%), and trouble failing asleep (33.3%). One hundred-and-four (92.0%) participants took some action to relieve at least one of their withdrawal symptoms during their index-quit attempt, including 26 (23.0%) participants who reported resuming cannabis use.
  
  
  CONCLUSIONS
  Cannabis withdrawal is a clinically significant feature of cannabis use among people with schizophrenia, may serve as a negative reinforcer for relapse, and deserves greater attention in treatment and research. Clinical Trials registration NCT00679016.
authors.affiliation: Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA.
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Boggs
authors.forename: Deanna L
authors.initials: DL
authors.lastname: Kelly
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.forename: Jared A
authors.initials: JA
authors.lastname: Linthicum
authors.forename: Hailey
authors.initials: H
authors.lastname: Turner
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Schroeder
authors.forename: Robert P
authors.initials: RP
authors.lastname: McMahon
authors.forename: David A
authors.initials: DA
authors.lastname: Gorelick
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology*; D008875:Middle Aged; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000453:epidemiology*; D012565:Schizophrenic Psychology; D013375:Substance Withdrawal Syndrome / Q000175:diagnosis / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D055815:Young Adult