Genetic counselling to reduce cannabis use and later mental illness risk
Tests genetic counselling to help teens and young adults reduce cannabis use.
Plain-language title generated from the registry record
Registry title: Genetic Counselling in the Prevention of Mental Health Consequences of Cannabis Use
Key facts
- Where
- Halifax, CanadaSee the site
AI summary: who the study is looking for
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for young people aged 12 to 21 who are already in the FORBOW study. Genetic counselling tries to lower the effects of cannabis on mental health.
- Age
- 12 to 21 years
- Sex
- All sexes can join.
- Disease stage
- People with a diagnosis of severe mental illness at baseline cannot join.
Main reasons for not taking part
- Diagnosis of severe mental illness at baseline (psychotic disorder, bipolar disorder, severe or recurrent depression)
- Autism or intellectual disability that interferes with assessment (IQ < 70)
- Not enrolled in the FORBOW study
- English not good enough to benefit from the intervention
- No capacity to give informed consent at the most recent FORBOW assessment
Read by machine on 12 November 2026.
Could this be for you?
Answer for yourself. This is not a decision: only the study team can say whether you can take part.
- Are you between 12 and 21 years old?
Source: NCT03601026, who can take part
Where in Canada
- Nova Scotia Health AuthorityHalifax, CanadaContact: Rudolf Uher, MD PhDTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Contact the study team: see the registry record → Contacts and Locations
Print a page for my doctorTrial details
- Who runs it
- Nova Scotia Health Authority
- Trial code
- NCT03601026
- Record updated
- 14 May 2025
- Original description
Severe mental illness (SMI) refers to the most burdensome psychiatric conditions. The need to pre-empt the onset of SMI is pressing because once SMI develops, quality of life is poor and available treatments have limited efficacy. Most risk factors for SMI are either unchangeable (e.g., genetics) or difficult to alter (e.g., low socio-economic status). In contrast, cannabis use is one specific risk factor that could be avoided. Certain individuals are more vulnerable to the harmful effects of cannabis. Genetic factors can help us identify these high-risk individuals. One in three individuals are carriers of a higher-risk genetic variant, and cannabis users with this genotype are at up to 7-fold increased risk of developing schizophrenia. In our study, genetic counselling will be provided to participants by a board-certified genetic counsellor. During the genetic counselling session, participants will have the option to receive their genotype. Participants will be counselled regarding their individualized risk of developing and of not developing SMI based on family history, whether or not they choose to use cannabis, and genotype (if the participants accept the genetic test results). The investigators hypothesize that this intervention will reduce exposure to cannabis compared to the youth who are not offered the intervention.Read full original descriptionShow less
Interdisciplinary Approach to Maximize Adolescent Potential: Genetic Counselling Interventions to Reduce Negative Environmental Effects
Severe mental illness (SMI) refers to the most burdensome psychiatric conditions. The need to pre-empt the onset of SMI is pressing because once SMI develops, quality of life is poor and available treatments have limited efficacy. Most risk factors for SMI are either unchangeable (e.g., genetics) or difficult to alter (e.g., low socio-economic status). In contrast, cannabis use is one specific risk factor that could be avoided. Certain individuals are more vulnerable to the harmful effects of cannabis. Genetic factors can help us identify these high-risk individuals. One in three individuals are carriers of a higher-risk genetic variant, and cannabis users with this genotype are at up to 7-fold increased risk of developing schizophrenia. In our study, genetic counselling will be provided to participants by a board-certified genetic counsellor. During the genetic counselling session, participants will have the option to receive their genotype. Participants will be counselled regarding their individualized risk of developing and of not developing SMI based on family history, whether or not they choose to use cannabis, and genotype (if the participants accept the genetic test results). The investigators hypothesize that this intervention will reduce exposure to cannabis compared to the youth who are not offered the intervention.
Inclusion: Enrolment in the Families Overcoming Risks and Building Opportunities for Well-being (FORBOW) study; Age between 12 and 21 years; Knowledge of English sufficient to benefit from the intervention; Capacity to provide informed consent at most recent FORBOW assessment; Provision of consent to be contacted about future studies at most recent FORBOW assessment.
Exclusion: A diagnosis of severe mental illness (psychotic disorder, bipolar disorder, severe/recurrent depression) at baseline; Autism or intellectual disability of a degree that interferes with assessment (IQ < 70).