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

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

19

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 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

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
Intervention / Treatment
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

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

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

Centre for Addiction and Mental Health

Investigators

  • 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)

November 6, 2017

Primary Completion (Actual)

December 30, 2019

Study Completion (Actual)

December 30, 2019

Study Registration Dates

First Submitted

July 25, 2018

First Submitted That Met QC Criteria

August 7, 2018

First Posted (Actual)

August 10, 2018

Study Record Updates

Last Update Posted (Actual)

September 5, 2023

Last Update Submitted That Met QC Criteria

September 1, 2023

Last Verified

September 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID 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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