Subclinical depressive symptoms and continued cannabis use: predictors of negative outcomes in first episode psychosis

PLoS One. 2015 Apr 15;10(4):e0123707. doi: 10.1371/journal.pone.0123707. eCollection 2015.

Abstract

Background: Although depressive symptoms in first episode psychosis have been associated with cannabis abuse, their influence on the long-term functional course of FEP patients who abuse cannabis is unknown. The aims of the study were to examine the influence of subclinical depressive symptoms on the long-term outcome in first episode-psychosis patients who were cannabis users and to assess the influence of these subclinical depressive symptoms on the ability to quit cannabis use.

Methods: 64 FEP patients who were cannabis users at baseline were followed-up for 5 years. Two groups were defined: (a) patients with subclinical depressive symptoms at least once during follow-up (DPG), and (b) patients without subclinical depressive symptoms during follow-up (NDPG). Psychotic symptoms were measured using the Positive and Negative Syndrome Scale (PANSS), depressive symptoms using the Hamilton Depression Rating Scale (HDRS)-17, and psychosocial functioning was assessed using the Global Assessment of Functioning (GAF). A linear mixed-effects model was used to analyze the combined influence of cannabis use and subclinical depressive symptomatology on the clinical outcome.

Results: Subclinical depressive symptoms were associated with continued abuse of cannabis during follow-up (β= 4.45; 95% confidence interval [CI]: 1.78 to 11.17; P = .001) and with worse functioning (β = -5.50; 95% CI: -9.02 to -0.33; P = .009).

Conclusions: Subclinical depressive symptoms and continued cannabis abuse during follow-up could be predictors of negative outcomes in FEP patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Analysis of Variance
  • Depression / diagnosis
  • Depression / etiology
  • Depression / psychology*
  • Female
  • Follow-Up Studies
  • Humans
  • Logistic Models
  • Male
  • Marijuana Abuse / complications
  • Marijuana Abuse / psychology*
  • Middle Aged
  • Prognosis
  • Psychiatric Status Rating Scales
  • Psychotic Disorders / complications
  • Psychotic Disorders / psychology*
  • Socioeconomic Factors
  • Time Factors
  • Young Adult

Grants and funding

This work was supported by health research funds from the Spanish Government (PS09/02002 CIBER Network; EC10-333, PI10/01430, PI10/01746, PI11/01977, PI11/02708, 2011/1064, 11-BI-01, 1677-DJ-030, and EC10-220); European Regional Development Funds, and local grants from the Basque Country Government (2008111010, 2009111047, 2010111170, 2010112009, 2011111110, 2011111113, SAIO10-PC10BF01, SAIO11-PE11BF006, SAIO11-PE11BF007, SAIO10-PR10BF01, GIC 10/80, and KRONIK 11/010); the Basque Foundation for Health Innovation and Research (BIOEF; BIO09/EM/010); the Spanish Clinical Research Network (CAIBER; 1392-D-079) and the University of the Basque Country (GIC10/80, US10/08, and EHU08/54). The psychiatric research department in University Hospital of Alava-Santiago is supported by the Stanley Research Foundation (03-RC-003). These institutions had no further role in the study design, data collection, analysis or interpretation, writing of the report, or in the decision to submit the paper for publication.