# Cannabis use following trauma exposure: An observational study of the impact of acute stress and fear response on cannabis outcomes

> **NIH NIH R01** · BROWN UNIVERSITY · 2022 · $731,930

## Abstract

PROJECT SUMMARY
Exposure to trauma is associated with a range of negative outcomes such as posttraumatic stress disorder
(PTSD) and substance use disorder, particularly cannabis. The early posttrauma period (i.e., the days, weeks,
and months following exposure) represents a critical period of risk for long term problem behaviors, especially
among emerging adults (aged 18-25), which constitutes continued development accompanied by a peak in
substance use and increased risk for trauma exposure. As regional laws, cultures, and beliefs about cannabis
use (CU) continue to shift, there is concern that trauma exposure may exacerbate use (via self-regulation) and
lead to greater cannabis-related problems, as many individuals report using cannabis to relieve distress,
hyperarousal, and other posttrauma symptoms. Furthermore, while the majority of US states that have
legalized cannabis for medical use include outcomes of stress and trauma, such as PTSD, as qualifying
conditions for a state-issued medical marijuana license, little is known about how cannabis may impact the
early post-trauma course. Given that the endocannabinoid system plays an essential role in regulating stress
response and learned fear, CU in the acute post-trauma period may alter mechanisms contributing to
alterations in fear neurocircuitry (e.g., alterations in consolidation/ reconsolidation, retrieval, extinction) and
physiological reactivity. Limited (and contradicting) evidence, however, regarding safety and efficacy of
cannabis preclude strong conclusions about its potential therapeutic role, with some prospective studies
demonstrating detrimental or no long-term effects of CU on PTSD symptoms. The overall goal of our study is
to examine the interplay between posttraumatic stress symptoms and cannabis use behavior during the period
immediately following trauma exposure. We will recruit and prospectively follow N=200 trauma-exposed
regular cannabis users admitted to the general hospital emergency department after medical evaluation for
traumatic injury. Upon discharge, participants will complete ecological momentary assessment (EMA) paired
with wearable biosensors (smartwatch) to record CU behavior, symptom development, and physiological
output (i.e., heart rate) during early trauma recovery. Participants will return for completion of clinical interview
and self-report, as well as laboratory procedures to characterize fear extinction and physiological reactivity.
The main goals of this research are to: (a) assess alterations in fear response and physiological reactivity
associated with CU, (b) characterize the impact of posttraumatic stress symptoms on cannabis use behaviors,
and (c) determine whether early markers of altered physiology and posttraumatic stress symptoms are makers
for trajectories of long-term adverse cannabis-related outcomes (i.e., use disorder, problems, chronic/heavy
use).

## Key facts

- **NIH application ID:** 10444156
- **Project number:** 1R01DA054116-01A1
- **Recipient organization:** BROWN UNIVERSITY
- **Principal Investigator:** Leslie Ann Daline Brick
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $731,930
- **Award type:** 1
- **Project period:** 2022-08-15 → 2027-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10444156

## Citation

> US National Institutes of Health, RePORTER application 10444156, Cannabis use following trauma exposure: An observational study of the impact of acute stress and fear response on cannabis outcomes (1R01DA054116-01A1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10444156. Licensed CC0.

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