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NCT Number: NCT05486234

CARS: Cannabis and Alcohol Reduction Study

The study will test a computerized treatment with subjects ages 13-17 years who are seeking treatment for alcohol and/or cannabis use. Follow-up assessments will be conducted at one- and three-months following treatment.

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Key information

Conditions

Cannabis Use Alcohol Drinking Alcohol Use, Unspecified Behavior Chemically-Induced Disorders Drinking Behavior Mental Disorders Substance Use Substance Use Disorders Substance-Related Disorders

Age range

13 year–17 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Medical University of South Carolina

Charleston, South Carolina, 29425, United States

Location status: Recruiting

Location contact

Austin Hahn, Ph.D.

CONTACT

854-444-9456

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • between the ages of 13 and 17
  • be seeking treatment for either cannabis or alcohol use;
  • report co-occurring alcohol and cannabis use during the past three months (i.e., participants who report using both alcohol and cannabis during the three months prior to participation in the study, regardless of if the use was simultaneous)
  • have a caregiver willing to participate and provide consent.

Treatment and study plan

modified Approach-Avoidance Task (mAAT), which aims to modify automatic approach bias

Behavioral

Participants will undergo a baseline assessment before completing computerized tasks. During the baseline assessment, participants will be asked questions about alcohol and cannabis use. We will also ask questions about the way participants think about things, past life experiences related to substance use, and questions about how participants feel about reducing their substance use. Then, participants will complete a series computerized tasks where they will push and pull a joystick in response to images that are presented on a screen or where they will try to get a high score. During the computerized tasks, we will also be measuring brain activity using EEG. During the study, participants will also be asked to respond to questions about their health and behavior using an app on a smartphone or tablet using a secure program. Participants in the Treatment Group will then complete four sessions of the modified Approach-Avoidance Task (mAAT), which aims to modify automatic approach bias.

modified Approach-Avoidance Task (mAAT) that does not aim to modify automatic approach bias.

Behavioral

Participants will undergo a baseline assessment before completing computerized tasks. During the baseline assessment, participants will be asked questions about alcohol and cannabis use. We will also ask questions about the way participants think about things, past life experiences related to substance use, and questions about how participants feel about reducing their substance use. Then, participants will complete a series computerized tasks where they will push and pull a joystick in response to images that are presented on a screen or where they will try to get a high score. During the computerized tasks, we will also be measuring brain activity using EEG. During the study, participants will also be asked to respond to questions about their health and behavior using an app on a smartphone or tablet using a secure program. Participants in the Control Group will then complete four sessions of an Approach-Avoidance Task (mAAT) that does not aim to modify automatic approach bias.

Primary outcomes

  1. Change in cannabis use as assessed by Timeline Followback

    Time frame: Baseline and Three-Month Follow-up

    The TLFB is a calendar-assisted semi-structured interview that will be used to assess cannabis and alcohol use since the last assessment. The TLFB will assess the number of days a person used cannabis over the past 90 days compared to the 90 days prior to enrolling in this study.

  2. Change in alcohol use as assessed by Timeline Followback

    Time frame: Baseline and Three-Month Follow-up

    The TLFB is a calendar-assisted semi-structured interview that will be used to assess cannabis and alcohol use since the last assessment. The TLFB will assess the number of days a person consumed alcohol over the past 90 days compared to the 90 days prior to enrolling in this study.

  3. Change in Cannabis Approach Bias (D-Score)

    Time frame: Baseline, One-Week Follow-up, and Three-Month Follow-up

    D scores will be calculated for each participant at baseline, posttest, and three-month follow-up. Participants' mean reaction times (RTs) during the approach cannabis trials will be subtracted from the mean avoid cannabis trial RTs. These scores are then divided by the SD across all cannabis trials. Positive scores indicate an approach bias for cannabis stimuli.

  4. Change Cannabis Approach Bias (D-Score)

    Time frame: Baseline, One-Week Follow-up, and Three-Month Follow-up

    D scores will be calculated for each participant at baseline, posttest, and three-month follow-up. Participants' mean reaction times (RTs) during the approach alcohol trials will be subtracted from the mean avoid alcohol trial RTs. These scores are then divided by the SD across all alcohol trials. Positive scores indicate an approach bias for alcohol stimuli.

Study contacts

Contact information is provided by the study sponsor or research team.

Austin M Hahn, Ph.D.

CONTACT

[email protected]

854-444-9456

Sponsors and collaborators

Lead sponsor

Medical University of South Carolina

Other

Collaborators

  • National Institute on Drug Abuse (NIDA)

Registry information

Official study title

Brief Computerized Intervention for Reducing Adolescent Cannabis and Alcohol Use

Acronym: CARS

Important dates

Study start
2023
Primary completion
2026
Study completion
2026
First posted
Aug 3, 2022
Registry last updated
Mar 9, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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