# Changes in cognition and psychiatric disorder symptoms during cannabis abstinence using a novel discordant twin design

> **NIH NIH K23** · UNIVERSITY OF COLORADO DENVER · 2022 · $53,686

## Abstract

PROJECT SUMMARY/ABSTRACT
 Changes in the legal landscape of cannabis have occurred simultaneously with increases in use among
adults. Research efforts have focused on examining consequences of use, however, characterizing the impact
of cannabis abstinence on health among regular cannabis users is also a relevant public health concern. Few
research studies have compared cognition or psychiatric disorder symptoms between abstinent cannabis users,
using contingency management (CM), to individuals in a control condition (monitoring), which does not require
changes in cannabis use. The current study aims to extend the findings to an older population, for a longer period
of cannabis abstinence, and to examine all cognitive domains. Thus, the first aim is to test the impact of cannabis
abstinence for 6 weeks (42 days) on memory, attention, processing speed, language, and executive function
(EFs) on adults, who are between 31 to 47 years old. The second aim is to explore how cannabis abstinence
effects psychiatric disorder symptoms. The third aim (exploratory) is to examine how genetic risk for various
psychiatric disorder symptoms by environment (cannabis abstinence versus continued use) interactions impact
cognition. The proposed study is novel in that we will use experimental manipulation to create discordance in
cannabis use among monozygotic (MZ) twin pairs. This research design will require significantly fewer resources
than large-scale randomized controlled trials because the use of MZ twin pairs requires a smaller sample size
and is still sufficiently powered to detect small effects. Fifty identical twin pairs (N=100), who are concordant on
cannabis use, will be recruited from the Colorado Twin Registry, which have all been genotyped. Each twin,
within a twin pair, will be randomly assigned to either CM, incentive-based protocol to promote abstinence, or
control, no changes in cannabis use requested, for 42 days. Participants will be assessed across 42 days on
measures of cognition and psychiatric disorder symptoms (baseline, day 14, day 28, and day 42). The method
proposed in this project could be used to understand other outcomes from cannabis abstinence (e.g., physical
health) or abstinence from other substances. The aims of the research project map on to the training goals: 1)
clinical trial methodology, 2) longitudinal statistical analysis, and 3) behavioral genetics. Experts in clinical trial
methodology, longitudinal statistical analysis, and behavioral genetics, will guide the research and training
program. The team of researchers consists of Drs. John Hewitt and Christian Hopfer (primary mentors, training
aim 3), Drs. Susan Mikulich-Gilbertson (mentor, training aim 2) and Naomi Friedman (consultant, training aim
2), Drs. Randi Schuster (co-mentor, training aim 1), Paula Riggs, and Kent Hutchison (consultants, training aim
1). Each training aim consists of one-on-one meetings with mentors or consultants, workshops, courses,
seminars, spec...

## Key facts

- **NIH application ID:** 10527851
- **Project number:** 3K23DA054212-01S1
- **Recipient organization:** UNIVERSITY OF COLORADO DENVER
- **Principal Investigator:** Jessica Megan Ross
- **Activity code:** K23 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $53,686
- **Award type:** 3
- **Project period:** 2021-09-01 → 2026-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10527851

## Citation

> US National Institutes of Health, RePORTER application 10527851, Changes in cognition and psychiatric disorder symptoms during cannabis abstinence using a novel discordant twin design (3K23DA054212-01S1). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10527851. Licensed CC0.

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