Boulder, Colorado 80304

  • Inflammatory Response


This study investigates whether the anxiolytic effects and anti-inflammatory properties of cannabis vary as a function of the ratio of CBD to THC, with the goal that these effects may shed light on the mixed data linking cannabis use and anxiety. Individuals with mild to moderate anxiety who elect to use cannabis (smoked flower or edible) will complete four weeks of observation. Participants complete cognitive tasks, a substance use history, health questionnaires concerning sleep and physical activity, and a blood draw at four different time points (Baseline, after 2 weeks of cannabis use, and immediately before and after self-administration after 4 weeks of use) with the use of a mobile pharmacology laboratory, which goes to a convenient location for each participant to self-administer their cannabis. Participants are then followed for five months to self-report on cannabis use, anxiety, subjective cognitive functioning, sleep quality, and other mental health symptoms.

Study summary:

Marijuana use is on the rise with the number of adults reporting medical and recreational use doubling in the past decade. Among adult medical marijuana users, 39% report using marijuana for the purposes of self-treating or coping with anxiety. Marijuana is approved for medical use in over half the states and is gaining traction for use as an "off-label" add-on therapy for treatment-resistant anxiety and stress-related disorders. Paradoxically, however, while data suggest that marijuana, in particular ∆9-tetrahydrocannabinol (THC), increases anxiety acutely, cross sectional and longitudinal data suggest associations between marijuana use and lower risk for anxiety disorders. There is some evidence demonstrating that marijuana use is associated with increases in acute anxiety and anxiety disorders. However, other data suggests that marijuana use may be protective for adolescents at-risk for anxiety and decrease the chances of developing an anxiety disorder during college. This finding is consistent with a growing body of evidence from animal models suggesting that marijuana has anxiolytic and anti-inflammatory properties. Clarifying the anxiolytic effects of specific strains that differ in their cannabinoid composition may explain these discrepant findings. Thus, regardless of whether results support or refute the anxiolytic properties of marijuana, findings from this study fill a critical void and can inform public perception. The study goal is to understand the anxiolytic effects of cannabinoids, in particular the effects of THC-based strains vs. CBD-based strains vs strains containing both THC and CBD in different ratios (1:0, 1:1, or 0:1) on inflammation, cognitive functioning, and anxiety/negative affect. This design will capitalize on the novel opportunity to examine the effects of real world marijuana strains on key outcomes.


Inclusion Criteria: - Non-users of cannabis must have been a non-user of cannabis for at least six months - If a user of cannabis, at least one episode of lifetime cannabis use and a desire to use cannabis to cope with anxiety. - Reports at least mild to moderate anxiety (≥5 on GAD-7) Exclusion Criteria: - Seeking treatment for a substance use disorder - Current use of other drugs (e.g., cocaine, methamphetamine) - Current use psychotropic or steroid-based medications - Has an immune-relevant disease (e.g. HIV) - Daily tobacco user - Currently pregnant or trying to become pregnant - In treatment for psychotic disorder, bipolar disorder or major depression disorder with suicidal ideation; or a history with these disorders.



Primary Contact:

Principal Investigator
Cinnamon Bidwell, PhD
University of Colorado, Boulder

Leah Hitchcock, PhD
Phone: 303-492-0288

Backup Contact:


Location Contact:

Boulder, Colorado 80304
United States

Leah Hitchcock, PhD

Site Status: Recruiting

Data Source:

Date Processed: September 18, 2021

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