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Author Notes:

Corresponding Author: Michael T. Compton, M.D., M.P.H., Lenox Hill Hospital, Department of Psychiatry, 111 E. 77th Street, New York, NY 10075. Tel: 212-434-3215, Fax: 212-434-3306, Email: mcompton@nshs.edu

The authors thank the staff and patients of Grady Health System, DeKalb Regional Crisis Center, and Georgia Regional Hospital at Atlanta, in Atlanta, Georgia; and The George Washington University Hospital, Washington Hospital Center, and United Medical Center, in Washington, D.C.

The funding source had no role in data analyses, the writing of the manuscript, or the decision to submit it for publication.


Research Funding:

This work was supported by grant R01 MH081011 from the National Institute of Mental Health to the last author.

Research reported in this publication was supported by National Institute of Mental Health grant R01 MH081011 (“First-Episode Psychosis and Pre-Onset Cannabis Use”) to the last author.


  • Science & Technology
  • Life Sciences & Biomedicine
  • Psychiatry
  • Age at onset
  • Cannabis
  • First-episode psychosis
  • Marijuana
  • Schizophrenia
  • AGE

Marijuana use in the immediate 5-year premorbid period is associated with increased risk of onset of schizophrenia and related psychotic disorders

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Journal Title:

Schizophrenia Research


Volume 171, Number 1-3


, Pages 62-67

Type of Work:

Article | Post-print: After Peer Review


Objectives: Several studies suggest that adolescent marijuana use predicts earlier age at onset of schizophrenia, which is a crucial prognostic indicator. Yet, many investigations have not adequately established a clear temporal relationship between the use and onset. Methods: We enrolled 247 first-episode psychosis patients from six psychiatric units and collected data on lifetime marijuana/alcohol/tobacco use, and ages at onset of prodrome and psychosis in 210 of these patients. Cox regression (survival analysis) was employed to quantify hazard ratios (HRs) for effects of diverse premorbid use variables on psychosis onset. Results: Escalation of premorbid use in the 5 years prior to onset was highly predictive of an increased risk for onset (e.g., increasing from no use to daily use, HR = 3.6, p < 0.0005). Through the analysis of time-specific measures, we determined that daily use approximately doubled the rate of onset (HR = 2.2, p < 0.0005), even after controlling for simultaneous alcohol/tobacco use. Building on previous studies, we were able to determine that cumulative marijuana exposure was associated with an increased rate of onset of psychosis (= 0.007), independent of gender and family history, and this is possibly the reason for age at initiation of marijuana use also being associated with rate of onset in this cohort. Conclusions: These data provide evidence of a clear temporal relationship between escalations in use in the five years pre-onset and an increased rate of onset, demonstrate that the strength of the association is similar pre- and post-onset of prodromal symptoms, and determine that early adult use may be just as important as adolescent use in these associations.

Copyright information:

© 2016 Elsevier B.V. Published by Elsevier Inc. All rights reserved.

This is an Open Access work distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).
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