Psychotic symptom and cannabis relapse in recent-onset psychosis. Prospective study.
BACKGROUND
Cannabis use appears to exacerbate psychotic symptoms and increase risk of psychotic relapse. However, the relative contribution of cannabis use compared with other risk factors is unclear. The influence of psychotic symptoms on cannabis use has received little attention.


OBJECTIVE
To examine the influence of cannabis use on psychotic symptom relapse and the influence of psychotic symptom severity on relapse in cannabis use in the 6 months following hospital admission.


METHODS
At baseline, 84 participants with recent-onset psychosis were assessed and 81 were followed up weekly for 6 months, using telephone and face-to-face interviews.


RESULTS
A higher frequency of cannabis use was predictive of psychotic relapse, after controlling for medication adherence, other substance use and duration of untreated psychosis. An increase in psychotic symptoms was predictive of relapse to cannabis use, and medication adherence reduced cannabis relapse risk.


CONCLUSIONS
The relationship between cannabis use and psychosis may be bidirectional, highlighting the need for early intervention programmes to target cannabis use and psychotic symptom severity in this population.
Hides
L
L
School of Applied Psychology, Griffith University, Melbourne, Victoria, Australia. lhides@unimelb.edu.au
Dawe
S
S
Kavanagh
D J
DJ
Young
R McD
RM
D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use; D001007:Anxiety / Q000150:complications; D003863:Depression / Q000150:complications; D005260:Female; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000523:psychology*; D010349:Patient Compliance; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000188:drug therapy / Q000209:etiology* / Q000523:psychology; D012008:Recurrence; D015203:Reproducibility of Results; D012307:Risk Factors; D012720:Severity of Illness Index; D019966:Substance-Related Disorders / Q000523:psychology; D016019:Survival Analysis
D014150:Antipsychotic Agents