Effects of cannabis on driving in young versus middle-aged users

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This study investigates how cannabis affects simulated driving performance in young and middle-aged drivers. Participants will be divided into two age groups and further categorized as occasional or frequent cannabis users. Each participant will attend two test sessions, where they will smoke either a cannabis cigarette or a placebo before driving in a simulator. Blood samples will be collected to measure THC levels, and cognitive tasks will be performed to assess the impact of cannabis on driving abilities.

Why it matters

Who can join: the full rules

Inclusion Criteria

* 19-25 or 35-45 years of age;
* Use of smoked cannabis at least once in the past 6 months.
* Use of smoked or vaped cannabis primarily for recreational purposes on up to 1 day per week or on at least 6 days per week in the past 3 months;
* Holds a class G or G2 Ontario driver's licence (or equivalent from another jurisdiction) for at least 12 months;
* Willing to abstain from using alcohol for 24 hours and cannabis for 72 hours prior to Practice and Test Sessions;
* Willing to abstain from all other drugs not prescribed for medical purposes for 48 hours prior to Practice and Test Sessions;
* Resides within Toronto (study site) or can reside with friends/family in Toronto after a Test Session; this area may be extended to the Greater Toronto area if recruitment challenges arise;
* Participant willing to use appropriate contraception until their participation in the study is completed;
* Provides written and informed consent.

Exclusion Criteria

* Use of cannabis primarily for therapeutic purposes, or equally for therapeutic and recreational purposes;
* Diagnosis of medical condition that contraindicates use of cannabis determined by self-report as judged by the Principal Investigator and a study physician; this includes a history of hypersensitivity to cannabinoids smoke, respiratory disease and/or severe cardiovascular, cerebrovascular, renal or liver disease, and bleeding disorders. Smoking cannabis is not recommended for individuals with respiratory diseases, and they will be excluded;
* Diagnosis of psychiatric condition that contraindicates use of cannabis determined by self-report or SCID-5;
* Participants of childbearing potential: Pregnancy (point-of-care test) or breastfeeding;
* Meets criteria for current or lifetime alcohol or other substance use disorder (DSM-5), except tobacco use disorder and caffeine use disorder;
* Is a regular user of medications that affect brain function (based on self-report); this includes concomitant therapy with sedative-hypnotics or other psychoactive drugs
* Use of anti-hypertensives;
* First-degree relative diagnosed with schizophrenia or another psychotic disorder.
* Participation in a past driving study at CAMH (to limit practice effects).
* Participation in a clinical study concurrent with their participation in this study.

Where it's running

• Centre for Addiction and Mental Health
  Toronto, Ontario, Canada Recruiting

Study contacts

• Principal investigator: Christine Wickens, PhD — Centre for Addiction and Mental Health
• Study coordinator: Christine Wickens, PhD
• Email: christine.wickens@camh.ca
• Phone: 416 535-8501

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.