title: A multi-center, randomized controlled trial of a group psychological intervention for psychosis with comorbid cannabis dependence over the early course of illness.
abstract: BACKGROUND
  Patients who experience the onset of psychotic illness with a comorbid diagnosis of cannabis dependence experience poor clinical outcomes. Few studies have identified interventions that reduce cannabis use and improve clinical outcome in this population.
  
  
  OBJECTIVE
  We undertook a multi-center, randomized controlled trial of a group psychological intervention for psychosis with comorbid cannabis dependence to determine whether there was any impact on cannabis use symptoms, global functioning, insight, attitudes to treatment and subjective quality of life.
  
  
  METHODS
  Across three centers, we compared a group psychological intervention, based on cognitive behavioral therapy and motivational interviewing, with treatment as usual among patients experiencing their first psychotic episode or early in the course of psychotic illness. Substance misuse and indices of clinical outcome were assessed at baseline, 3months and 1year.
  
  
  RESULTS
  At 3month and 1year follow-ups, there was no evidence for an intervention effect on cannabis use, symptoms, global functioning insight or attitude to treatment. However, the intervention improved subjective quality of life at 3months and this effect was sustained at 1year.
  
  
  CONCLUSIONS
  Over the early phase of psychotic illness, group psychological interventions for those with comorbid cannabis dependence improved subjective quality of life. However, this was not associated with reduction in use of cannabis or improvement in clinical outcomes.
authors.affiliation: St. John of God Adult Mental Health Services, Cluain Mhuire Family Centre, Blackrock, Co. Dublin, Ireland; DETECT Early Intervention in Psychosis Service, Blackrock, Co. Dublin, Ireland. kevin.madigan@sjog.ie
authors.forename: Kevin
authors.initials: K
authors.lastname: Madigan
authors.forename: Daria
authors.initials: D
authors.lastname: Brennan
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Lawlor
authors.forename: Niall
authors.initials: N
authors.lastname: Turner
authors.forename: Anthony
authors.initials: A
authors.lastname: Kinsella
authors.forename: John J
authors.initials: JJ
authors.lastname: O'Connor
authors.forename: Vincent
authors.initials: V
authors.lastname: Russell
authors.forename: John L
authors.initials: JL
authors.lastname: Waddington
authors.forename: Eadbhard
authors.initials: E
authors.lastname: O'Callaghan
mesh_terms: D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D001290:Attitude; D015928:Cognitive Behavioral Therapy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology*; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000453:epidemiology* / Q000523:psychology / Q000534:rehabilitation*; D011788:Quality of Life; D012008:Recurrence; D012720:Severity of Illness Index; D055815:Young Adult