Impact of Cannabis Consumption on Psychotic Symptoms and Reality Monitoring in Patients With Schizophrenia: a Real-life Study (F_r_IEND-3)

March 13, 2026 updated by: Centre Hospitalier Charles Perrens, Bordeaux
This study aims to examine the dual effects of cannabis consumption on both positive and negative symptoms of schizophrenia, across laboratory and real-world contexts. By integrating ecological momentary assessment (EMA) with cognitive tasks such as reality monitoring, the research seeks to clarify how cannabis use influences symptom severity and cognitive functioning in individuals with schizophrenia. Gaining insight into these relationships may contribute to the development of more effective management strategies and ultimately improve outcomes for patients living with schizophrenia.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Schizophrenia is a complex psychiatric disorder that affects approximately 1% of the general population, typically emerging in early adulthood. It is characterized by a wide range of symptoms, including positive symptoms (e.g., hallucinations and delusions), negative symptoms (e.g., apathy and emotional blunting), and cognitive impairments. The disorder contributes substantially to the global burden of disease, ranking among the top 30 causes of disability-adjusted life years.

Cannabis use is common among individuals with schizophrenia, with estimates suggesting that between 16% and 42% of patients have used cannabis at some point in their lives. The relationship between cannabis use and schizophrenia is multifactorial. Cannabis consumption has been associated with an increased risk of psychosis, worsening of positive symptoms, and earlier onset of the disorder. However, some studies indicate that cannabis may also exert beneficial effects on negative symptoms, potentially mediated by compounds other than THC.

Cognitive deficits are a core feature of schizophrenia, particularly impairments in reality monitoring. Reality monitoring refers to the ability to distinguish between internally generated events (intrinsic) and those originating from external sources (extrinsic). In schizophrenia, this capacity is often compromised, leading to misattributions of internal thoughts to external sources, which may contribute to the development of positive symptoms such as hallucinations.

Given the dynamic nature of symptoms and substance use in schizophrenia, traditional clinical models may fail to capture the complexity of these interactions. Ecological Momentary Assessment (EMA) provides a novel approach by leveraging mobile devices to collect real-time data on symptoms, substance use, and cognitive performance in everyday life. EMA has been validated in schizophrenia research, offering high-resolution data that can complement and enhance traditional models.

Study Type

Interventional

Enrollment (Estimated)

120

Phase

  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • DSM-5 diagnosis of schizophrenia or schizo-affective disorder with the following clinical features:

    • Clinically stable and in the residual (non-acute) phase of illness,
    • No change in antipsychotic treatment for at least 1 month,
    • Outpatient, ambulatory care,
    • No uncontrolled positive symptoms (assessed using PANSS)
  • Patients able to use a mobile phone.
  • Capacity and willingness to give informed consent.
  • Must be able to read, speak, and understand French
  • Patients subscribing to the French national medical insurance.
  • Patients under "curatelle" (partial guardianship) are eligible

Exclusion Criteria:

Patient under "tutelle" (full legal guardianship).

  • Psychiatric comorbidities: autism, bipolar disorder.
  • Current criteria for any other substance use disorder except for nicotine use disorder.
  • Any medical condition hindering the study and/or use of the smartphone application.
  • Patients with somatic, cognitive or other disorders preventing the use of the device (deafness, impaired vision, illiteracy….).
  • Pregnant or breastfeeding woman.
  • Patients who are not proficient in French.
  • Subject included in clinical and/or therapeutic experimentation in progress.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: "Cannabis user" group (SZ-CUD)
Use of Ecological Momentary Assessment (EMA) and a mobile Reality Monitoring task
Other: Ecological Momentary Assessment (EMA) and Reality Monitoring tasks
Use of Ecological Momentary Assessment (EMA) and a mobile Reality Monitoring task
Active Comparator: "Non-cannabis user" group (SZ-noCUD)
Use of Ecological Momentary Assessment (EMA) and a mobile Reality Monitoring task
Other: Ecological Momentary Assessment (EMA) and Reality Monitoring tasks
Use of Ecological Momentary Assessment (EMA) and a mobile Reality Monitoring task

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Presence of a statistically significant association between cannabis consumption and the reduction of negative symptoms
Time Frame: 8 days
Presence of a statistically significant association between cannabis consumption and the exacerbation of positive symptoms with EMA scale
8 days
Presence of a statistically significant association between cannabis consumption and the exacerbation of positive symptoms
Time Frame: 8 days
Presence of a statistically significant association between cannabis consumption and the reduction of negative symptoms with EMA scale
8 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Centre Hospitalier Charles Perrens, Bordeaux

Investigators

  • Study Director: David MISDRAHI, MD, Centre Hospitalier Charles Perrens

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

June 1, 2026

Primary Completion (Estimated)

December 31, 2027

Study Completion (Estimated)

December 31, 2028

Study Registration Dates

First Submitted

November 24, 2025

First Submitted That Met QC Criteria

December 15, 2025

First Posted (Actual)

December 30, 2025

Study Record Updates

Last Update Posted (Actual)

March 16, 2026

Last Update Submitted That Met QC Criteria

March 13, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2025-A01055-44

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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