Changes in Cognition and Psychiatric Disorder Symptoms During Cannabis Abstinence Using a Novel Discordant Twin Design

• ClinicalTrials.gov Identifier: NCT05160688
• Recruitment Status: Not yet recruiting
• First Posted: December 16, 2021
• Last Update Posted: August 11, 2022
• Sponsor: University of Colorado, Denver
• Collaborator: University of Colorado, Boulder
• Information provided by (Responsible Party): University of Colorado, Denver

Tracking Information

• First Submitted Date: November 19, 2021
• First Posted Date: December 16, 2021
• Last Update Posted Date: August 11, 2022
• Estimated Study Start Date: September 1, 2022
• Estimated Primary Completion Date: February 1, 2026 (Final data collection date for primary outcome measure)

Current Primary Outcome Measures (submitted: December 2, 2021)

• Change in attention performance [ Time Frame: Change from baseline to day 42 ]
  Flanker Inhibitory Control and Attention Test on NIH Toolbox: Composite score of accuracy and reaction time
• Change in episodic memory [ Time Frame: Change from baseline to day 42 ]
  Picture Sequence Memory Test on NIH Toolbox: Cumulative number of correct adjacent pairs
• Change in working memory [ Time Frame: Change from baseline to day 42 ]
  List Sorting Working Memory Test on NIH Toolbox: Total items correct across all trials
• Change in receptive vocabulary [ Time Frame: Change from baseline to day 42 ]
  Picture Vocabulary Test on NIH Toolbox: Computer adaptive testing
• Change in reading decoding [ Time Frame: Change from baseline to day 42 ]
  Oral Reading Recognition Test: Number of letters and words read correctly
• Change in immediate memory/verbal learning [ Time Frame: Change from baseline to day 4 ]
  Auditory Verbal Learning Test on NIH Toolbox: Total number of words recalled
• Change in pattern comparison processing speed [ Time Frame: Change from baseline to day 42 ]
  Pattern Comparison Processing Speed Test: Total number of correct responses
• Change in oral symbol digit test processing speed [ Time Frame: Change from baseline to day 42 ]
  Oral Symbol Digit Test on NIH Toolbox: Total number of correctly identified symbols
• Change in attention and executive function [ Time Frame: Change from baseline to day 42 ]
  Dimensional Change Card Sort Test on NIH Toolbox: Composite score of accuracy and correct answers

• Original Primary Outcome Measures: Same as current

Current Secondary Outcome Measures (submitted: December 2, 2021)

• Change in anxiety symptoms [ Time Frame: Change from baseline to day 42 ]
  Beck Anxiety Inventory: Total score. Scores range from 0-63 and higher scores indicate higher levels of anxiety.
• Change in depressive symptoms [ Time Frame: Change from baseline to day 42 ]
  Beck Depression Inventory: Total score. Scores range from 0-63 and higher scores indicate greater levels of depression.
• Change in attention deficit/hyperactivity disorder symptoms [ Time Frame: Change from baseline to day 42 ]
  Adult Self-Report Scale: Total score. Scores range from 0-72 and higher scores indicate greater level of symptoms of attention deficit/hyperactivity disorder.

• Original Secondary Outcome Measures: Same as current
• Current Other Pre-specified Outcome Measures: Not Provided
• Original Other Pre-specified Outcome Measures: Not Provided

Descriptive Information

• Brief Title: Changes in Cognition and Psychiatric Disorder Symptoms During Cannabis Abstinence Using a Novel Discordant Twin Design
• Official Title: Changes in Cognition and Psychiatric Disorder Symptoms During Cannabis Abstinence Using a Novel Discordant Twin Design
• Brief Summary: This study will test whether 42 days of cannabis abstinence, compared to continued cannabis use, is associated with improvements in cognition and psychiatric disorder symptoms. Identical twins, who are concordant on cannabis use, will be experimentally-manipulated to be discordant for 42 days. Each twin, within a twin pair, will be randomly assigned to either the contingency management condition, incentive-based protocol to promote cannabis abstinence, or control condition, no changes in cannabis use requested.

Detailed Description

The proposed project is a randomized controlled trial to compare cognition and psychiatric disorder symptoms between monozygotic (MZ) twin pairs, who are concordant on frequency of cannabis use. Each twin, within the twin pair, will be randomly assigned to either contingency management (CM), monetary incentives provided to reinforce cannabis abstinence, or control, no changes in cannabis use required or reinforced. Participants in the CM condition will receive an increasing schedule of payments at each visit reinforcing continued cannabis abstinence. All participants will receive increases in the payment schedule for attendance of each subsequent assessment. Participants will be assessed on measures of cognition including attention, memory, and processing speed as well as anxiety, depression, and ADHD symptoms. In addition, at each visit participants will complete a qualitative and quantitative drug test. The qualitative drug test will be used to determine if new cannabis use has occurred since the last visit, and will determine if the participant receives payment for abstinence. The investigators will also use previously collected genotype for each participant.

The first aim of this study is to characterize cognitive recovery, across all potential cognitive domains, using an experimental manipulation to achieve discordance between MZ twins on cannabis use. The hypothesis for the first aim is that the abstinent group will have greater improvements in memory and processing speed compared to controls. However, there will not be any group differences between the abstinent group and the control group on attention, language, and executive function performance. The second aim of the proposed project is to characterize psychiatric disorder symptoms by comparing psychiatric disorder symptom changes among the cannabis abstaining twin to their cannabis using co-twin across 42 days. The abstinent group will endorse more psychiatric symptoms during the withdrawal period (up to 14 days) but will endorse fewer psychiatric symptoms at day 28 and 42 compared to the control group. The third aim (exploratory) of the proposed project is to examine how genetic risk for psychiatric disorders interacts with environment (i.e., cannabis abstinence versus continued use) to influence cognitive functioning. The hypothesis for aim 3 is that anxiety, depression, and ADHD polygenic scores will be more strongly associated with cognitive outcomes in the control group compared to the abstinent group.

• Study Type: Interventional
• Study Phase: Not Applicable
• Study Design: Allocation: Randomized; Intervention Model: Parallel Assignment; Masking: None (Open Label); Primary Purpose: Basic Science
• Condition: Cannabis

Intervention

Behavioral: Contingency management

Participants will be paid to abstain from cannabis use.

Study Arms

• Experimental: Contingency management
  Contingency management (CM) is an incentive-based intervention providing patients with tangible rewards as reinforcement for positive behaviors like abstinence from drug use. Incentives are provided with each urine sample that is drug-free and are increased with each subsequent drug-free urine sample. Participants in the CM condition will receive increasing payments for abstinence: $30 on day 3, $45 on day 5, $60 on day 7, $75 on day 14, $90 on day 21, $105 on day 28, and $120 on day 42. Participants in both conditions also receive increasing payment for visit attendance: $10 on day 1, $15 on day 3, $20 on day 5, $25 on day 7, $30 on day 14, $35 on day 21, $45 on day 28, and $55 on day 42. At the end of the baseline visit, participants in the CM condition will sign a behavioral contract with study staff that clearly outlines expectations as well as the payment schedule.
  Intervention: Behavioral: Contingency management
• No Intervention: No intervention
  Participants in this condition will be monitored and will not receive any compensation for cannabis abstinence.

• Publications *: Not Provided

Recruitment Information

• Recruitment Status: Not yet recruiting
• Estimated Enrollment (submitted: December 2, 2021): 100
• Original Estimated Enrollment: Same as current
• Estimated Study Completion Date: February 1, 2026
• Estimated Primary Completion Date: February 1, 2026 (Final data collection date for primary outcome measure)

Eligibility Criteria

Inclusion Criteria:

1. Monozygotic (MZ) twin pair, in which both twins are willing to participate
2. MZ twin pair must be concordant in their frequency of cannabis use (+/- 2 days)
3. Cannabis use at least 1x per week on most weeks
4. Cannabis use in the past 7 days at the baseline visit
5. Positive qualitative urine toxicology at baseline for THC
6. Located within the state of Colorado

Exclusion Criteria:

1) Discordance in the twin pairs on a significant, adverse experience, like traumatic brain injury.

Sex/Gender

• Sexes Eligible for Study: All

• Ages: 31 Years to 47 Years (Adult)
• Accepts Healthy Volunteers: Yes

Contacts

Contact: J. Megan Ross, Ph.D.; 303-724-6387; Jessica.M.Ross@cuanschutz.edu

• Listed Location Countries: Not Provided

Administrative Information

• NCT Number: NCT05160688
• Other Study ID Numbers: 21-4899
• Has Data Monitoring Committee: No

U.S. FDA-regulated Product

• Studies a U.S. FDA-regulated Drug Product: No
• Studies a U.S. FDA-regulated Device Product: No

IPD Sharing Statement

• Plan to Share IPD: No
• Plan Description: In accordance with NIH data sharing policies, data produced from this project will be made available to ensure timely translation of research results to improve human health. The investigators believe there is a possibility of deductive disclosure of subjects with unusual characteristics, even though all identifiers would be removed prior to release for sharing. Thus, the investigators will make the data and associated documentation available to users only under a specific data-sharing agreement that requires: (1) a commitment to using the data only for research purposes and not to identify any individual participant; (2) a commitment to securing the data using appropriate computer technology; and (3) a commitment to destroying or returning the data after analyses are completed.

• Current Responsible Party: University of Colorado, Denver
• Original Responsible Party: Same as current
• Current Study Sponsor: University of Colorado, Denver
• Original Study Sponsor: Same as current
• Collaborators: University of Colorado, Boulder

Investigators

• Principal Investigator: J. Megan Ross, Ph.D.; University of Colorado - Anschutz Medical Campus

• PRS Account: University of Colorado, Denver
• Verification Date: August 2022