# Impact of Marijuana Legalization: Comparison of Two Longitudinal Twin Cohorts

> **NIH NIH R01** · UNIVERSITY OF COLORADO DENVER · 2020 · $154,303

## Abstract

This supplemental grant proposes to add questions to extend the aims of the parent project by collecting
additional data related to COVID-19 including financial hardships, social/interpersonal problems, stress, mental
health, and substance use changes. Data will also be collected on whether participants are essential workers,
were exposed to COVID-19, or have been diagnosed with COVID-19.
Parent grant Aim 1: Effect of RML on substance use/misuse, mental health, & psychosocial function
Aim 1 extended: Effect of COVID-19 pandemic and RML on substance use/misuse, mental health &
psychosocial function.
We will test the hypothesis that access to RML increases the likelihood that the stress and disruption
associated with COVID-19 will lead to increased marijuana use and abuse. Relatedly, we will test the extent to
which increased marijuana use, related to RML and stress/disruptions from COVID-19, is accompanied by
increases in other substance use, mental health disorders, or psychosocial dysfunction.
Parent grant Aim 2: Individual differences in the effect of RML
Aim 2 extended: Examine individual differences in the effect of COVID-19 pandemic and RML.
Examine individual differences in the effects of COVID-19 and legalization by leveraging parallel multi-wave
longitudinal twin studies in CO and MN, which both began collecting substance use, psychopathology, and
psychosocial function during the twins' adolescence. This supplemental assessment will allow us to: a) identify
how COVID-19 differentially impacts individuals depending on legalization and prior exposure to marijuana; b)
examine how individuals differ in their vulnerability and resilience to the effects COVID-19, in the context of
legalization, based on their individual level of risk (e.g., prior diagnosis of anxiety or depression); and c)
examine if there are differential associations between COVID-19 and substance use/dependence, mental
health, and psychosocial problems depending on legalization status and gender.

## Key facts

- **NIH application ID:** 10192397
- **Project number:** 3R01DA042755-04S1
- **Recipient organization:** UNIVERSITY OF COLORADO DENVER
- **Principal Investigator:** JOHN K. HEWITT
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $154,303
- **Award type:** 3
- **Project period:** 2017-09-01 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10192397

## Citation

> US National Institutes of Health, RePORTER application 10192397, Impact of Marijuana Legalization: Comparison of Two Longitudinal Twin Cohorts (3R01DA042755-04S1). Retrieved via AI Analytics 2026-05-31 from https://api.ai-analytics.org/grant/nih/10192397. Licensed CC0.

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