Effects of Cannabis Abstinence on Symptoms and Cognition in Depression

September 1, 2023 updated by: Tony George, Centre for Addiction and Mental Health

Effects of Extended Cannabis Abstinence on Symptoms and Cognition in Depressed Individuals

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
19

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Canada
    • Ontario
      • Toronto, Ontario, Canada, M6J1H4
        • Centre for Addiction and Mental Health

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 55 years (Adult)

Accepts Healthy Volunteers

No

Description

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

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: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: 28-Day Cannabis Abstinence
The study will assess the changes that occur after a 28-day abstinence period in patients with Major Depressive Disorder (MDD) and comorbid Cannabis Use Disorder (CUD). Patients will be instructed to initiate abstinence 12 hours prior to the baseline session and will come in for weekly visits involving a series of clinical, cognitive, and substance use assessments.
Behavioral: Weekly Behavioral Coaching Session
The participants will be provided with a 20-minute individual behavioral support session weekly for 4 weeks (28 days of abstinence), designed to provide them with tools and techniques to manage the craving and withdrawal symptoms that occur with cessation.
Behavioral: Contingency Management
If the participant's weekly abstinence is successful as determined by the urine results on day 28, the participant will receive an additional $300.00 cash bonus on top of their hourly $10 compensation for attending all visits. We predict that this cash bonus is enough incentive to allow for the behavioural change of abstinence in this patient population.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
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).
Time Frame: Weekly (Day 0, Day 7, Day 14, Day 21, Day 28) and at 8 weeks (Follow-up Day 56)
The clinical assessment will be administered weekly during the abstinence period and conducted by study personnel. The HRDS is used to evaluate depression on a 17-item scale with higher values indicating worse depressive symptoms.
Weekly (Day 0, Day 7, Day 14, Day 21, Day 28) and at 8 weeks (Follow-up Day 56)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
The effects of 28 day cannabis abstinence on change in cognitive function in cannabis dependent patients with Major Depressive Disorder (MDD) as assessed by a cognitive battery administered at Baseline, Week 2, Endpoint and Follow-Up.
Time Frame: Bi-Weekly (Day 0, Day 14, Day 28) and at 8 Weeks (Follow-up Day 56)
The cognitive battery will include the primary outcome of verbal memory (assessed by Hopkins Verbal Learning Test) and will be compared to baseline (Day 1) performance. Cortical inhibition will also be assessed and compared.
Bi-Weekly (Day 0, Day 14, Day 28) and at 8 Weeks (Follow-up Day 56)
The effects of 28 day cannabis abstinence on change in co-occurring anxiety in cannabis dependent patients with MDD as assessed by the Beck Anxiety Inventory (BAI) administered weekly.
Time Frame: Weekly (Day 0, Day 7, Day 14, Day 21, Day 28) and at 8 weeks (Follow-up Day 56)
The clinical assessment will be administered at Baseline, weekly during the abstinence period and Follow-up and will be conducted by study personnel. The BAI is a 21-item scale used to evaluate the severity of anxiety symptoms with higher values indicating worse outcomes.
Weekly (Day 0, Day 7, Day 14, Day 21, Day 28) and at 8 weeks (Follow-up Day 56)

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Centre for Addiction and Mental Health

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Tony George, M.D., FRCPC, Centre for Addiction and Mental Health

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 (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 6, 2017

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 30, 2019

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 30, 2019

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 25, 2018

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 7, 2018

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 10, 2018

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 5, 2023

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 1, 2023

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 069/2017

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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