Changes in Cognition and Psychiatric Disorder Symptoms During Cannabis Abstinence Using a Novel Discordant Twin Design
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Contingency management.
- Who it may be relevant to
- Registry conditions: Cannabis. Basic parameters: 31 years — 47 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- United States
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Overview
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.
Interventions
- Behavioral Contingency management
Participants will be paid to abstain from cannabis use.
Primary outcome measures
- Change in attention performance [Time frame: Change from baseline to day 42]
- Change in episodic memory [Time frame: Change from baseline to day 42]
- Change in working memory [Time frame: Change from baseline to day 42]
- Change in receptive vocabulary [Time frame: Change from baseline to day 42]
- Change in reading decoding [Time frame: Change from baseline to day 42]
- Change in immediate memory/verbal learning [Time frame: Change from baseline to day 4]
- Change in pattern comparison processing speed [Time frame: Change from baseline to day 42]
- Change in oral symbol digit test processing speed [Time frame: Change from baseline to day 42]
- Change in attention and executive function [Time frame: Change from baseline to day 42]
Secondary outcome measures (3)
- Change in anxiety symptoms [Time frame: Change from baseline to day 42]
- Change in depressive symptoms [Time frame: Change from baseline to day 42]
- Change in attention deficit/hyperactivity disorder symptoms [Time frame: Change from baseline to day 42]
Eligibility criteria
Inclusion criteria
- Monozygotic (MZ) twin pair, in which both twins are willing to participate
- MZ twin pair must be concordant in their frequency of cannabis use (+/- 2 days)
- Cannabis use at least 1x per week on most weeks
- Cannabis use in the past 7 days at the baseline visit
- Positive qualitative urine toxicology at baseline for THC
- Located within the state of Colorado
Exclusion criteria
1\) Discordance in the twin pairs on a significant, adverse experience, like traumatic brain injury.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- Randomized
- Model
- Parallel assignment
- Masking
- Open label
- Primary purpose
- Basic science
Study locations
United States · 1 center
- Jessica M Ross — Aurora
Identifiers
NCT: NCT05160688 · 21-4899