Effects of Cannabis Abstinence on Symptoms and Cognition in Depression (NCT03624933) | Clinical Trial Compass
CompletedNot Applicable
Effects of Cannabis Abstinence on Symptoms and Cognition in Depression
Canada19 participantsStarted 2017-11-06
Plain-language summary
The objective of this study is to assess the changes in symptoms and cognition that occur after a 28-day abstinence period in patients with comorbid Cannabis Use Disorder (CUD) and Major Depression (MDD). This study employs a 28-day abstinence paradigm a total of 8 visits to the CAMH Russell site (screening, training, baseline, week 1, week 2, week 3, week 4, follow-up). Participants should be between the ages of 18-55, meet criteria for moderate depression and CUD, be non-treatment seeking, and be on a stable dose of antidepressant medication. The study visits will take up a total of approximately 22.5 hours with compensation for time provided. These visits will involve multiple clinical, substance use, and cognitive assessments. Abstinence will be maintained by weekly behavioural coaching sessions and contingency reinforcement.
Who can participate
Age range
18 Years – 55 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* ages 18-55
* meet DSM-5 diagnostic criteria for cannabis use disorder (cannabis use \>1 g/day, CUDIT score \>12)
* meet DSM-5 diagnostic criteria for Major Depressive Disorder as determined using the SCID
* be an outpatient receiving a stable dose of antidepressant medication(s) for at least 1 month
* have a Hamilton Depression Rating Scale (HDRS-17) baseline total score greater than 14
* have a Full Scale IQ greater than 80 as determined by the WTAR
* be a non-treatment seeking cannabis user
* evidence of sufficient motivation and effort as measure by a Test of Memory Malingering (TOMM) score greater than 45
* urinary baseline THC-COOH levels greater than 150 ng/ml
Exclusion Criteria:
* meets criteria for abuse or dependence of alcohol or other illicit substances within the part 6 months (with the exception of cannabis, nicotine, or caffeine)
* positive urine screen for illicit substances other than cannabis, nicotine or caffeine
* current suicidal or homicidal ideation
* psychotic disorder diagnosis (e.g. schizoaffective disorder, major depression with psychotic features) as determined by the SCID
* head injury with loss of consciousness greater than 2 minutes or requiring hospitalization
* neurological or medical condition determined to effect cognition
* be treatment seeking for cannabis use
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
The effects of 28 day cannabis abstinence on change in depressive symptoms in cannabis-dependent patients with Major Depressive Disorder (MDD) as assessed by the Hamilton Rating Scale for Depression (HRSD).
Timeframe: Weekly (Day 0, Day 7, Day 14, Day 21, Day 28) and at 8 weeks (Follow-up Day 56)