PMID- 25654244
OWN - NLM
STAT- MEDLINE
DCOM- 20160217
LR  - 20220316
IS  - 1469-8978 (Electronic)
IS  - 0033-2917 (Linking)
VI  - 45
IP  - 9
DP  - 2015 Jul
TI  - Course of cannabis use and clinical outcome in patients with non-affective 
      psychosis: a 3-year follow-up study.
PG  - 1977-88
LID - 10.1017/S0033291714003092 [doi]
AB  - BACKGROUND: Prospective studies on the relationship between course of cannabis 
      use and clinical outcome in patients with non-affective psychotic disorders are 
      inconclusive. The current study examined whether (1) persistent, recently 
      started, discontinued and non-cannabis-using patients with a psychotic disorder 
      differed with regard to illness outcome at 3-year follow-up, and (2) whether 
      timing of cannabis discontinuation was associated with course of clinical 
      outcome. METHOD: This 3-year follow-up study was part of a multi-center study in 
      the Netherlands and Belgium (Genetic Risk and Outcome of Psychosis; GROUP). We 
      used mixed-model analyses to investigate the association between pattern of 
      cannabis use and symptoms, global functioning and psychotic relapse. RESULTS: In 
      our sample of 678 patients, we found persistent users to have more positive and 
      general symptoms, worse global functioning and more psychotic relapses compared 
      with non-users and discontinued users [Positive and Negative Syndrome Scale 
      (PANSS) positive, p < 0.001; PANSS general, p < 0.001; Global Assessment of 
      Functioning (GAF) symptoms, p = 0.017; GAF disability, p < 0.001; relapses, 
      p = 0.038]. Patients who started using cannabis after study onset were 
      characterized by worse functioning at baseline and showed an increase in general 
      symptoms (including depression and anxiety) at the 3-year follow-up (p = 0.005). 
      Timing of cannabis discontinuation was not associated with clinical outcome. 
      CONCLUSIONS: These findings suggest that cannabis use in patients with a 
      psychotic disorder has a long-lasting negative effect on illness outcome, 
      particularly when persistent. Treatment should focus on discouraging cannabis 
      use.
FAU - van der Meer, F J
AU  - van der Meer FJ
AD  - Department of Early Psychosis,Academic Medical Center,Amsterdam,The Netherlands.
FAU - Velthorst, E
AU  - Velthorst E
AD  - Department of Early Psychosis,Academic Medical Center,Amsterdam,The Netherlands.
CN  - Genetic Risk and Outcome of Psychosis (GROUP) Investigators
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20150205
PL  - England
TA  - Psychol Med
JT  - Psychological medicine
JID - 1254142
SB  - IM
MH  - Adult
MH  - Anxiety/psychology
MH  - Belgium/epidemiology
MH  - Case-Control Studies
MH  - Depression/psychology
MH  - Disease Progression
MH  - Female
MH  - Follow-Up Studies
MH  - Humans
MH  - Longitudinal Studies
MH  - Male
MH  - Marijuana Abuse/epidemiology/*psychology
MH  - Marijuana Smoking/epidemiology/*psychology
MH  - Netherlands/epidemiology
MH  - Prospective Studies
MH  - Psychotic Disorders/epidemiology/*psychology
MH  - Retrospective Studies
MH  - Young Adult
OTO - NOTNLM
OT  - Cannabis
OT  - clinical outcome
OT  - psychosis
OT  - psychotic relapse
OT  - schizophrenia
OT  - symptoms
FIR - Bruggeman, Richard
IR  - Bruggeman R
FIR - Cahn, Wiepke
IR  - Cahn W
FIR - de Haan, Lieuwe
IR  - de Haan L
FIR - Kahn, Rene S
IR  - Kahn RS
FIR - Meijer, Carin
IR  - Meijer C
FIR - Myin-Germeys, Inez
IR  - Myin-Germeys I
FIR - van Os, Jim
IR  - van Os J
FIR - Wiersma, Durk
IR  - Wiersma D
EDAT- 2015/02/06 06:00
MHDA- 2016/02/18 06:00
CRDT- 2015/02/06 06:00
PHST- 2015/02/06 06:00 [entrez]
PHST- 2015/02/06 06:00 [pubmed]
PHST- 2016/02/18 06:00 [medline]
AID - S0033291714003092 [pii]
AID - 10.1017/S0033291714003092 [doi]
PST - ppublish
SO  - Psychol Med. 2015 Jul;45(9):1977-88. doi: 10.1017/S0033291714003092. Epub 2015 
      Feb 5.