Developing and Strengthening Cannabis Warnings: Warning Message Testing

The purpose of this activity is to identify promising cannabis warning messages from different themes. Participants will be adults who live in the United States, including both people who use cannabis and those who do not use cannabis. In an online within-subjects experiment, participants will be randomly assigned to view 7 cannabis warning messages from different themes developed as part of previous study activities. After viewing each cannabis warning message, participants will rate the message on awareness, clarity, believability, cognitive elaboration, perceived message effectiveness, and reactance. The survey will take 15-20 minutes.

Study Overview

• Status: Not yet recruiting
• Conditions: Marijuana Use; Cannabis
• Intervention / Treatment: Behavioral: Constituents; Behavioral: Cognitive Functioning; Behavioral: Cardiovascular Health; Behavioral: Motor Vehicle Crashes; Behavioral: Dependence; Behavioral: Psychosis and Schizophrenia; Behavioral: Mental Health; Behavioral: Reproductive Health; Behavioral: Respiratory Health; Behavioral: Edibles; Behavioral: Cannabis Hyperemesis Syndrome; Behavioral: Control

Detailed Description

The purpose of this activity is to identify promising cannabis warning messages from different themes.

Setting: An online survey of adults who live in the United States.

Participants: An estimated N=1500 adults who live in the United States, including both people who use cannabis and those who do not use cannabis. Participants will be recruited by Qualtrics Services. Participants who are eligible for the study will view a consent form as part of the survey and check a box to indicate that they agree to participate in the study. Once the participant has completed consent, they will be able to begin the survey.

Procedures: Participants will complete a within-subjects experiment in which they view and rate cannabis warning messages from different themes. Participants will be screened for inclusion and answer questions on demographic information and susceptibility to cannabis use. Participants will then be randomly assigned to view 7 cannabis warning messages from different themes developed as part of previous study activities. After viewing each cannabis warning message, participants will rate the message on awareness, clarity, believability, cognitive elaboration, perceived message effectiveness, and reactance. There will be a total of 11 warning themes plus control. After viewing and rating their assigned cannabis warning messages, participants will answer additional questions about cannabis risk perceptions and use behavior (if applicable), additional demographic information, and about their use of tobacco and alcohol. The survey will take 15-20 minutes.

• Study Type: Interventional
• Enrollment (Estimated): 1500
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Sarah D Kowitt, PhD, MPH; Phone Number: 919-974-4980; Email: kowitt@unc.edu

Study Locations

• United States
  • North Carolina
    • Chapel Hill, North Carolina, United States, 27514
      • University of North Carolina at Chapel Hill
      • Contact: Sarah D Kowitt, PhD, MPH; Phone Number: 919-974-4980; Email: kowitt@unc.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age 18 years of age and older
• Live in the United States

Exclusion Criteria:

• Age less than 18 years of age
• Does not live in the United States

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Cannabis warning messages; Participants will view and rate 7 cannabis warning messages. The cannabis warning messages cover 11 different themes plus a control theme and were identified in a previous study activity. Theme 1: Constituents Theme 2: Cognitive Functioning Theme 3: Cardiovascular Health Theme 4: Motor Vehicle Crashes Theme 5: Dependence Theme 6: Psychosis and Schizophrenia Theme 7: Mental Health Theme 8: Reproductive Health Theme 9: Respiratory Health Theme 10: Edibles Theme 11: Cannabis Hyperemesis Syndrome Theme 12: Control

Behavioral: Constituents; Participants will view and rate a message about constituents.; Behavioral: Cognitive Functioning; Participants will view and rate a message about cognitive functioning.; Behavioral: Cardiovascular Health; Participants will view and rate a message about cardiovascular health.; Behavioral: Motor Vehicle Crashes; Participants will view and rate a message about motor vehicle crashes.; Behavioral: Dependence; Participants will view and rate a message about dependence.; Behavioral: Psychosis and Schizophrenia; Participants will view and rate a message about psychosis and schizophrenia.; Behavioral: Mental Health; Participants will view and rate a message about mental health.; Behavioral: Reproductive Health; Participants will view and rate a message about reproductive health.; Behavioral: Respiratory Health; Participants will view and rate a message about respiratory health.; Behavioral: Edibles; Participants will view and rate a message about edibles.; Behavioral: Cannabis Hyperemesis Syndrome; Participants will view and rate a message about cannabis hyperemesis syndrome.; Behavioral: Control; Participants will view and rate a control message.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cognitive Elaboration	A one item measure of cognitive elaboration to assess how much a message makes the participant think about the health risks of cannabis. Response options are on a 5-point scale from 5='A great deal' to 1= 'Not at all', with higher scores indicating higher cognitive elaboration.	Baseline (one time online survey)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Perceived Message Effectiveness	This survey item assesses perceived message effectiveness in terms of how concerned the message makes the participant feel about the health effects of using cannabis. Response options are on a 5-point scale from 5='A great deal' to 1='Not at all' with higher scores indicating higher perceived message effectiveness.	Baseline (one time online survey)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clarity	This survey item assesses the extent to which a participant feels that the message is clear. Response options are on a 5-point scale from 5='Very clear' to 1='Not clear at all' with higher scores indicating that a message is more clear.	Baseline (one time online survey)
Believability	This survey item assesses the extent to which a participant feels that the message is believable. Response options are on a 5-point scale from 5='Very believable' to 1='Not at all believable' with higher scores indicating that a message is more believable.	Baseline (one time online survey)
Reactance	This survey item assesses reactance in terms of how much a participant is annoyed by the message. Response options are on a 5-point scale from 5='A great deal' to 1='Not at all' with higher scores indicating higher reactance to the message.	Baseline (one time online survey)

Collaborators and Investigators

• Sponsor: University of North Carolina, Chapel Hill
• Collaborators: National Institute on Drug Abuse (NIDA)
• Investigators: Principal Investigator: Sarah D Kowitt, PhD, MPH, University of North Carolina, Chapel Hill; Principal Investigator: Leah M Ranney, PhD, MA, University of North Carolina, Chapel Hill

Study record dates

Study Major Dates

• Study Start (Estimated): July 13, 2026
• Primary Completion (Estimated): November 30, 2026
• Study Completion (Estimated): November 30, 2026

Study Registration Dates

• First Submitted: June 25, 2026
• First Submitted That Met QC Criteria: July 8, 2026
• First Posted (Actual): July 13, 2026

Study Record Updates

• Last Update Posted (Actual): July 13, 2026
• Last Update Submitted That Met QC Criteria: July 8, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Cannabis; Health Communication; Marijuana Use; Product Packaging; Product Labeling; Warnings
• Additional Relevant MeSH Terms: Mental Disorders; Substance-Related Disorders; Chemically-Induced Disorders; Behavior; Marijuana Use; Marijuana Abuse; Public Health; Environment and Public Health; Health Services; Health Care Facilities Workforce and Services; Population Characteristics; Rehabilitation; Health Status; Demography; Epidemiologic Measurements; Activities of Daily Living; Health; Functional Status; Mental Health; Reproductive Health
• Other Study ID Numbers: 24-1616; R01DA058003 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: A de-identified version of individual participant data will be shared through the UNC Dataverse
• IPD Sharing Time Frame: The dataset will be available after data collection and analysis and will remain available for 10 years
• IPD Sharing Access Criteria: Open Access
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No