title: Continued cannabis use at one year follow up is associated with elevated mood and lower global functioning in bipolar I disorder.
abstract: BACKGROUND
  There is limited knowledge about how environmental factors affect the course of bipolar disorder (BD). Cannabis has been proposed as a potential risk factor for poorer course of illness, but the role of cannabis use has not been studied in a first treatment BD I sample.
  
  
  METHODS
  The present study examines the associations between course of illness in first treatment BD I and continued cannabis use, from baseline to one year follow up. Patients (N = 62) with first treatment DSM-IV BD I were included as part of the Thematically Organized Psychosis study (TOP), and completed interviews and self-report questionnaires at both baseline and follow up. Cannabis use within the last six months at baseline and use between baseline and follow up ("continued use") was recorded.
  
  
  RESULTS
  After controlling for confounders, continued cannabis use was significantly associated with elevated mood (YMRS) and inferior global functioning (GAF-F) at follow up. Elevated mood mediated the effect of cannabis use on global functioning.
  
  
  CONCLUSIONS
  These results suggest that cannabis use has clinical implications for the early course of BD by increasing mood level. More focus on reducing cannabis use in clinical settings seems to be useful for improving outcome in early phase of the disorder.
authors: NORMENT, KG Jebsen Center for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital and Institute of Clinical Medicine, University of Oslo, Norway TOP Study, Building 49, Oslo University Hospital, Ullevål, Kirkeveien 166, PO Box 4956 Nydalen, 0424, Oslo, Norway. l.r.kvitland@medisin.uio.no.
authors: Levi Roestad
authors: LR
authors: Kvitland
authors: NORMENT, KG Jebsen Center for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital and Institute of Clinical Medicine, University of Oslo, Norway TOP Study, Building 49, Oslo University Hospital, Ullevål, Kirkeveien 166, PO Box 4956 Nydalen, 0424, Oslo, Norway. Ingrid.melle@medisin.uio.no.
authors: Ingrid
authors: I
authors: Melle
authors: NORMENT, KG Jebsen Center for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital and Institute of Clinical Medicine, University of Oslo, Norway TOP Study, Building 49, Oslo University Hospital, Ullevål, Kirkeveien 166, PO Box 4956 Nydalen, 0424, Oslo, Norway. s.r.aminoff@medisin.uio.no.|Division of Mental Health Services, Department of Specialized Inpatient Treatment, Akershus University Hospital, Akershus, Norway. s.r.aminoff@medisin.uio.no.
authors: Sofie Ragnhild
authors: SR
authors: Aminoff
authors: NORMENT, KG Jebsen Center for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital and Institute of Clinical Medicine, University of Oslo, Norway TOP Study, Building 49, Oslo University Hospital, Ullevål, Kirkeveien 166, PO Box 4956 Nydalen, 0424, Oslo, Norway. christine.demmo@medisin.uio.no.
authors: Christine
authors: C
authors: Demmo
authors: NORMENT, KG Jebsen Center for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital and Institute of Clinical Medicine, University of Oslo, Norway TOP Study, Building 49, Oslo University Hospital, Ullevål, Kirkeveien 166, PO Box 4956 Nydalen, 0424, Oslo, Norway. t.v.lagerberg@medisin.uio.no.
authors: Trine Vik
authors: TV
authors: Lagerberg
authors: NORMENT, KG Jebsen Center for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital and Institute of Clinical Medicine, University of Oslo, Norway TOP Study, Building 49, Oslo University Hospital, Ullevål, Kirkeveien 166, PO Box 4956 Nydalen, 0424, Oslo, Norway. o.a.andreassen@medisin.uio.no.
authors: Ole Andreas
authors: OA
authors: Andreassen
authors: Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway. p.a.ringen@medisin.uio.no.
authors: Petter Andreas
authors: PA
authors: Ringen
mesh_terms: D000223:Adaptation, Psychological / Q000187:drug effects / Q000502:physiology; D000328:Adult; D000339:Affect / Q000187:drug effects*; D001714:Bipolar Disorder / Q000523:psychology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008385:Marijuana Smoking / Q000009:adverse effects* / Q000503:physiopathology / Q000523:psychology*; D011788:Quality of Life / Q000523:psychology
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