Mobile Application-Based Interventions for Cannabis Use in Young Adults With First Episode Psychosis (Mobile Health)

September 3, 2026 updated by: Centre hospitalier de l'Université de Montréal (CHUM)

Psychotic disorders affect approximately 4% of Canadians and have a significant impact on individuals' well-being, their families and social networks, and healthcare systems. The development of psychosis is explained by a complex interplay of genetic and environmental factors, including the use of psychoactive substances. Frequent cannabis use can contribute to the development of psychotic disorders.

The prevalence of cannabis use disorder (CUD) in individuals with a first-episode psychosis (FEP) followed in Early Intervention Services (EIS) is 42-53%, well above that of the general population (~3%). Cannabis use in individuals with psychosis is associated with increased symptom severity, higher rates of relapse and hospitalization, and poor psychosocial functioning.

Standardized mobile app-based interventions offer a scalable and accessible solution. Our team developed and piloted CHAMPS (harm reduction) and iCanChange (use reduction/cessation) with favourable results: retention 82% (CHAMPS) and 84-86% (iCC), high satisfaction, and preliminary efficacy signals. The two pilot studies were targeting feasibility, this study is studying efficacy of the two app-based interventions (CHAMPS and iCanChange).

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

550

Phase

  • Not Applicable

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

Study Contact Backup

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

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

CHAMPS INTERVENTION

  • Young adults (18-35 years) with FEP
  • Cannabis use ≥1 day in the past month
  • MPS score ≥2,
  • NOT seeking treatment for cannabis use disorder (CUD).
  • CUD diagnosis possible but not required.
  • With a minimum of 2 months of follow-up at an EIS clinic.

I CAN CHANGE INTERVENTION

  • Young adults (18-35 years) with FEP and CUD (DSM-5, moderate to severe)
  • Seeking to reduce or cease use
  • With a minimum of 2 months of follow-up at an EIS clinic.

Exclusion Criteria:

  • Pregnancy, breastfeeding, or any medical condition that, in the opinion of the psychiatrist, precludes safe participation or the ability to provide informed consent,
  • Any disabling, unstable, or acute mental condition that, in the opinion of the psychiatrist, precludes safe participation or the ability to provide informed consent,
  • Any planned extended absence (pending legal action, surgery, inpatient program) or other reason that, in the opinion of the study team, might prevent completion of the study,
  • Presence of a substance use disorder that, in the opinion of the psychiatrist, precludes safe participation (e.g., very unstable or severe SUD),
  • Currently participating in another specific cannabis use-focused intervention.

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: Supportive Care
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: CHAMPS - intervention group
Participants who receive the CHAMPS intervention
Other: CHAMPS

CHAMPS is a psychosocial e-intervention grounded in motivational interviewing (MI) and harm reduction principles, developed using the Behavioral Change Wheel (BCW) theoretical framework.

CHAMPS is delivered through a mobile health platform and comprises 6 sequential psychotherapeutic modules (5-15 minutes each) plus a booster session:

Module 1: Automatic personalized feedback on current cannabis PBS based on baseline assessment, with improvement suggestions and identification of strengths that facilitate change.

Module 2: Exploration of personal values and the potential benefits of safer cannabis use practices Module 3: Evidence-based cannabis PBS using interactive psychoeducational techniques Module 4: Goal-setting using the SMART technique; participants define their own realistic cannabis-focused goals Module 5: Review of goal progress; support to revise current goal or adopt new consumption habits Module 6: Reassessment of consumption habits (PBS)
No Intervention: CHAMPS - no intervention group
Participants who are not receiving the CHAMPS intervention and are compared to the one who do
Experimental: I Can Change - Intervention group
Participants who receive the I Can Change intervention
Other: I Can Change

iCanChange (iCC) is a mobile app-based psychological intervention that incorporates principles of CBT, MI, and psychoeducation. It is available on Android and iPhone, in both English and French. Section 1 (10 modules): Modules 1 to 9 address topics such as cannabis dependence, myths, and its effects on psychosis, while helping users identify personal triggers, strengths, and benefits of reducing use. Section 1 concludes with Module 10, in which participants self-identify a flexible, person-oriented cannabis use goal such as reducing or stopping use. Two weeks after Module 10, an additional module is offered (up to two times) to consolidate and review goals.

Section 2 (8 modules): Modules aim at increasing coping skills, equipping users with practical tools to maintain progress, planning cannabis-free activities, building social support, managing stress, and adopting a healthy lifestyle. Booster modules (3 sessions, one per month during the 12-week follow-up)
No Intervention: I Can Change - No intervention group
Participants who are not receiving the I Can Change intervention and are compared to the one who do

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
CHAMPS Primary Outcome Measure
Time Frame: Week 8 post randomization
To determine whether adding CHAMPS (an intervention aimed at developing safer consumption behaviors) to standard EIS is superior to standard EIS alone in reducing cannabis-related problems in young adults with FEP who are not seeking to cease or reduce their use. Total score of the Marijuana Problems Scale (MPS, 19 items, 0-38) at Week 8 post-randomization (also assessed at Week 12 post-randomization). Minimum clinically important difference (MCID): 2 points. For each MPS item, the participant rates a cannabis-related problem over the past month on a three-point scale: 0 = not a problem, 1 = a minor problem, 2 = a serious problem. Total scores range from 0 to 38; higher scores indicate more serious problems.
Week 8 post randomization
I Can Change Primary Outcome Measure
Time Frame: Week 12 post randomization
To determine whether adding iCC to standard services offered in EIS clinics is superior to standard EIS alone in reducing the frequency of cannabis use in individuals with FEP and CUD (moderate to severe) who are seeking to reduce or cease their use. Number of days of cannabis use in the past 14 days (Timeline Follow Back, TLFB) at Week 12 (also assessed at Weeks 6 and 24 post-randomization).
Week 12 post randomization

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
CHAMPS secondary Outcome Measure
Time Frame: week 0-8-12
Number of days of cannabis use in the past 14 days - Timeline Follow Back (TFLB) The TLFB will assess self-reported days of cannabis use over the past 14 days , as well as type of cannabis products, provenance, form, and quantity . The main endpoint for this outcome is the number of days per week of cannabis use. Days per week is the preferred manner of reporting cannabis use frequency in the field, and use of cannabis once per week or more is an established threshold for increased risk of adverse psychosis-related outcomes.
week 0-8-12
CHAMPS secondary Outcome Measure
Time Frame: week 0-8-12
Protective behavioral strategies: PBSM total score (17 items, 15-73) The PBSM is a 17-item, self-report measure including various evidence-based strategies that cannabis users can adopt to reduce harms or use more safely. For each item, participants rate the degree to which they engage in a specific protective behavior on a scale of 1 = Never to 6 = Always. Individual item responses are summed for a total score, which is then converted to an item-response theory scaled score (possible range: 15-73). Higher scaled scores indicate greater use of PBS.
week 0-8-12
CHAMPS secondary Outcome Measure
Time Frame: week 0-8-12
The proportion of participants in each State of Change Designation (i.e., precontemplation, contemplation, and action) Readiness to change Questionnaire (RCQ) Motivation to change cannabis use practices will be assessed using the adapted 12-item Readiness-to-Change Questionnaire (RCQ), modified for cannabis use. The RCQ is based on Prochaska and DiClemente's stages-of-change model and assesses three stages: pre-contemplation, contemplation, and action. For each scale, 4 items are summed (range: -8 to +8); the scale with the highest score represents the participant's Stage of Change Designation. The internal consistency of the three subscales is acceptable. The tool is designed for cannabis users not seeking treatment who may be unaware of a problem.
week 0-8-12
CHAMPS secondary Outcome Measure
Time Frame: week 0-8-12
Quality of life: WHOQOL-BREF (26 items, 4 domains, 0-100) Quality of life will be measured using the WHOQOL-BREF, which assesses four domains: physical health, psychological health, social relationships, and environment, plus two overall items. The WHOQOL-BREF consists of 26 items; each item is rated on a 5-point Likert scale ranging from very poor to very good. Domain scores are calculated according to WHOQOL-BREF guidelines and converted to a 0-100 scale; an overall total score will also be calculated .
week 0-8-12
I Can Change Secondary Outcome Measure
Time Frame: Week 0-6-12-24
Cannabis dependence severity will be assessed using the Severity of Dependence Scale (SDS), a 5-item self-report questionnaire validated in people with early psychosis. Items are scored 0-3; total scores range from 0-15 (higher = greater dependence severity).
Week 0-6-12-24
I Can Change Secondary Outcome Measure
Time Frame: Week 0-6-12-24
Motivation to reduce cannabis use will be assessed using the Precaution Adoption Process Model (PAPM), a theoretical stage-based model that classifies individuals into 6 nominal stages: (1) unaware, (2) unengaged, (3) undecided, (4) decided not to act, (5) decided to act, (6) acting. Stages will be dichotomized for inter-group comparison (e.g., pre-action vs. action stages).
Week 0-6-12-24
I Can Change Secondary Outcome Measure
Time Frame: Week 0-6-12-24
In addition to frequency (primary endpoint), the timeline follow back (TLFB) will capture continuous abstinence (proportion of participants with 0 days of cannabis use in past 14 days) and estimated quantity of cannabis used per session.
Week 0-6-12-24
I Can Change Secondary Outcome Measure
Time Frame: Week 0-6-12-24
Quality of life will be measured using the WHOQOL-BREF, which has been validated in individuals with psychotic disorders and consists of 26 items across 4 domains: physical health, psychological health, social relationships, and environment. Each item is rated on a 5-point Likert scale ranging from very poor to very good. For each domain, scores are calculated according to WHOQOL-BREF guidelines and converted to a 0-100 scale.
Week 0-6-12-24

Collaborators and Investigators

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

Sponsor

Centre hospitalier de l'Université de Montréal (CHUM)

Collaborators

Ottawa Hospital Research Institute
Nova Scotia Health Authority
Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de Montreal
Integrated University Health and Social Services Center of the Capitale-Nationale
Centre Intégré de Santé et de Services Sociaux de la Montérégie-Centre

Investigators

  • Principal Investigator: Didier Jutras-Aswad, MD, Centre Hospitalier de l'Université de Montréal (CHUM)

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)

September 15, 2026

Primary Completion (Estimated)

September 15, 2030

Study Completion (Estimated)

April 15, 2031

Study Registration Dates

First Submitted

June 15, 2026

First Submitted That Met QC Criteria

September 3, 2026

First Posted (Actual)

September 10, 2026

Study Record Updates

Last Update Posted (Actual)

September 10, 2026

Last Update Submitted That Met QC Criteria

September 3, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • MP-02-2026-13381

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

Research personnel will inform participants that all information collected will remain strictly confidential to the extent prescribed by law, and that no individually identifiable information will be revealed in any publication or presentation. Only authorized persons having an authentication code and designated data access group have access to the REDCap databases. Protection, detection and correction measures are implemented to maintain data confidential. A potential breach of confidentiality, notably regarding substance use, could conceivably result in negative legal or social consequences.

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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