Cannabis users with first psychosis had more excitement symptoms initially but responded better to treatment

Among 175 antipsychotic-naive first-episode psychosis patients, those with recent cannabis use showed higher excitement symptoms and worse functioning at baseline, but had better treatment response for excitement and positive symptoms at 10-week follow-up.

Coutinho, Luccas S et al.·Schizophrenia research. Cognition·2019·Moderate EvidenceProspective Cohort
RTHC-01994Prospective CohortModerate Evidence2019RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Prospective Cohort
Evidence
Moderate Evidence
Sample
N=175

What This Study Found

Acute cannabis users had higher excitement symptoms and worse functioning at baseline. However, at 10-week follow-up, they showed higher response rates for excitement and positive symptoms than non-users. More days of recent cannabis use predicted worse functionality at baseline but not at follow-up, suggesting the acute cannabis effects resolved with treatment.

Key Numbers

175 patients at baseline, 99 at follow-up. All antipsychotic-naive. Acute cannabis users: higher excitement symptoms, worse baseline functioning. Better 10-week response for excitement and positive symptoms. Cannabis effects on functioning resolved by follow-up.

How They Did This

Prospective cohort study in Sao Paulo, Brazil. 175 antipsychotic-naive first-episode psychosis patients assessed at baseline, 99 reassessed at 10-week follow-up. Cannabis exposure variables: acute use, lifetime use, age at first use.

Why This Research Matters

Studying antipsychotic-naive patients eliminates a major confound in psychosis research. The finding that cannabis-related symptoms resolve well with treatment suggests they may represent a pharmacologically modifiable component of the psychotic presentation.

The Bigger Picture

The better treatment response in cannabis-using FEP patients is consistent with the theory that cannabis-precipitated psychosis may be a distinct and potentially more treatable subtype, at least in the short term.

What This Study Doesn't Tell Us

Significant attrition (175 to 99 at follow-up). Self-reported cannabis use. Short 10-week follow-up. Brazilian population may not generalize. Cannot determine whether the better response reflects a different illness subtype or resolution of acute cannabis effects.

Questions This Raises

  • ?Would the treatment advantage persist with longer follow-up?
  • ?Does cannabis cessation improve outcomes further?
  • ?Could excitement symptoms at FEP presentation serve as a clinical marker for recent cannabis use?

Trust & Context

Key Stat:
Better treatment response
Evidence Grade:
Rated moderate because this is a prospective study of antipsychotic-naive patients (eliminating a key confound), though attrition and short follow-up are limitations.
Study Age:
Published in 2019.
Original Title:
Cannabis acute use impacts symptoms and functionality in a cohort of antipsychotic naïve First Episode of Psychosis individuals.
Published In:
Schizophrenia research. Cognition, 16, 12-16 (2019)
Database ID:
RTHC-01994

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-ControlFollows or compares groups over time
This study
Cross-Sectional / Observational
Case Report / Animal Study

Enrolls participants and follows them forward in time.

What do these levels mean? →

Frequently Asked Questions

Does cannabis use affect psychosis treatment response?

In this study, patients with recent cannabis use at their first psychotic episode actually responded better to treatment at 10 weeks, particularly for excitement and positive symptoms.

Should clinicians look for cannabis use in first psychosis?

Higher excitement symptoms at first psychotic presentation may indicate recent cannabis use. This is clinically relevant because these symptoms appear to respond well to standard treatment.

Read More on RethinkTHC

Cite This Study

RTHC-01994·https://rethinkthc.com/research/RTHC-01994

APA

Coutinho, Luccas S; Honorato, Hianna; Higuchi, Cinthia H; Cavalcante, Daniel A; Belangeiro, Sintia; Noto, Mariane; Bressan, Rodrigo A; Cordeiro, Quirino; Noto, Cristiano; Gadelha, Ary. (2019). Cannabis acute use impacts symptoms and functionality in a cohort of antipsychotic naïve First Episode of Psychosis individuals.. Schizophrenia research. Cognition, 16, 12-16. https://doi.org/10.1016/j.scog.2018.10.002

MLA

Coutinho, Luccas S, et al. "Cannabis acute use impacts symptoms and functionality in a cohort of antipsychotic naïve First Episode of Psychosis individuals.." Schizophrenia research. Cognition, 2019. https://doi.org/10.1016/j.scog.2018.10.002

RethinkTHC

RethinkTHC Research Database. "Cannabis acute use impacts symptoms and functionality in a c..." RTHC-01994. Retrieved from https://rethinkthc.com/research/coutinho-2019-cannabis-acute-use-impacts

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.