Effects of Cannabis Abstinence on Symptomology and Cognition in Bipolar Disorder

Study Overview
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Brief Summary
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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 Bipolar (Type I or II) disorder. Stabilized bipolar patients (N=52) with CUD will be randomly assigned to one of two groups: 1) A contingent reinforcement (CR) group (n=26); 2) a non-contingent reinforcement (NCR) group (n=26). The study will include a total of 8 visits to the CAMH Russell site (screening, training, baselines, week 1-4, follow-up). Participants should be between the ages of 18-60, meet criteria for CUD (moderate to severe), meet criteria for Bipolar Disorder, be on a stable dose of mood stabilizing medication(s), and be non-treatment seeking cannabis user. The visits will take up a total of approximately 22.5 hours with compensation for time provided for both groups. These visits will involve multiple clinical, substance use, and cognitive assessments. Abstinence will be maintained by weekly behavioural coaching sessions and contingency reinforcement for the CR group.

Official Title
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Effects of Extended Cannabis Abstinence on Clinical and Cognitive Outcomes in Patients With Co-Morbid Bipolar Disorder and Cannabis Use Disorder

Conditions
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Cannabis Use Disorder, Bipolar Disorder, Cognition

Intervention / Treatment
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* Behavioral: Weekly Behavioral Coaching Session


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All participants must be between the ages 18-60 Meet SCID for DSM-5 diagnostic criteria for cannabis use disorder, moderate to severe Meet SCID for DSM-5 diagnostic criteria for Bipolar Disorder (Type I or II) Be an outpatient receiving a stable dose of mood stabilizing medication(s) for at least one month Have a Hamilton Depression Rating Scale (HDRS-17) baseline assessment in the range of 12-25 Have a Full-Scale IQ of at least 80 as determined by the WTAR Be a non-treatment seeking cannabis user Evidence of sufficient motivation and effort as measured by a Test of Memory Malingering (TOMM) score of at least 45 Y-MRS baseline score in the range of 0-15 Exclusion Criteria: Meets criteria for abuse or dependence of alcohol or other illicit substances within the past 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 Treatment seeking for cannabis use Head Injury > 5 minutes LOC Exceed upper and lower cut-offs on HSRD-17 and YMRS

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Randomized open-label trial to compare two arms: 1) contingent reinforcement and 2) non-contingent reinforcement.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Contingent Reinforcement<br>The Contingent Reinforcement (CR) group (n=26) will be given an abstinence bonus at the successful completion of a 28-Day cannabis abstinence verified by self-report and urinary THC-COOH level <20 ng/ml. | Behavioral: Weekly Behavioral Coaching Session<br>* The participants will be provided with a 20-minute individual behavioral support session weekly for 4 weeks (28 days abstinence), designed to provide them with tools and techniques to manage the craving and withdrawal symptoms that occur with cessation.<br>|
| Experimental: No Contingent Reinforcement<br>The Non-Contingent Reinforcement (NCR) group (n=26) will not be given an abstinence bonus at the successful completion of a 28-Day cannabis abstinence. | Behavioral: Weekly Behavioral Coaching Session<br>* The participants will be provided with a 20-minute individual behavioral support session weekly for 4 weeks (28 days abstinence), designed to provide them with tools and techniques to manage the craving and withdrawal symptoms that occur with cessation.<br>|

What is the study measuring?
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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 bipolar disorder as assessed by the Hamilton Rating Scale for Depression (HRSD). | The clinical assessment will be administered weekly during the abstinence period and conducted by study personnel. | Weekly (Day 0, Day 7, Day 14, Day 21, Day 28) and at 8 weeks (Follow-up Day 56) | 
| The effects of 28 day cannabis abstinence on change in hypomania symptoms in cannabis-dependent patients with bipolar disorder as assessed by the Young Mania Rating Scale (YMRS). | The clinical assessment will be administered weekly during the abstinence period and conducted by study personnel. | 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 bipolar disorder as assessed by a cognitive battery administered at Baseline, Week 2, Endpoint and Follow-Up. | The cognitive battery will include the primary outcome of motivation and effort (assessed by TOMM) 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 bipolar disorder as assessed by the Beck Anxiety Inventory (BAI). | The clinical assessment will be administered at Baseline, weekly during the abstinence period and Follow-up and will be conducted by study personnel. | Weekly (Day 0, Day 7, Day 14, Day 21, Day 28) and at 8 weeks (Follow-up Day 56) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Bipolar Disorder, Cannabis Use Disorder, Cognitive Function