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Completed

NCT Number: NCT04567238

Impact of Reduced Cannabis Use on Functional Outcomes (R33 Phase)

Nearly 20 million Americans report use of cannabis in the past month, and heavy cannabis use has increased by nearly 60% in the U.S. since 2007. Heavy cannabis use is associated with lower educational attainment, reduced physical activity, increased rates of addiction and unemployment, and neuropsychological deficits. Studies suggest that cannabis use is also associated with increased mental health symptoms, drugged driving, and traffic accidents. While there is evidence that sustained abstinence can lead to improvements in the functional outcomes of former users, the degree to which reductions alone (i.e., not sustained abstinence) in cannabis use might be associated with positive changes in functional outcomes is unknown. This is a critical gap in the literature, as many interventions for cannabis and other drugs are associated with decreases in frequency and quantity of use, but fail to achieve an effect on overall abstinence rates. The objective of the present research is to use ecological momentary assessment (EMA), a real-time, naturalistic data collection method, to prospectively study the impact of reduced cannabis use on functional outcomes in heavy cannabis users. Contingency management (CM) will be used to promote reductions in frequency and quantity of cannabis use. CM is an intensive behavioral therapy that is highly effective at producing short-term reductions in illicit drug use. We have recently developed a novel approach that leverages mobile technology and recent developments in cannabis testing. We have pilot-tested this approach with heavy cannabis users and found that it is an acceptable and feasible method. The present research will use this technology in conjunction with EMA methods to study the impact of reduced cannabis use on key functional outcomes. Our central hypothesis is that reductions in frequency and quantity of cannabis use will lead to positive changes in cannabis users' mental health, self-efficacy, physical activity, working memory, health-related quality of life, and driving behavior. The rationale for this research is that it will provide the first and only real-time data concerning the potential impact of reductions in cannabis use on functional outcomes. As such, the findings from the present research will directly inform ongoing efforts to include reductions in illicit drug use as a valid, clinically-meaningful outcome measure in clinical trials of pharmacotherapies for the treatment of substance use disorders.

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Key information

Conditions

Cannabis Cannabis Use Chemically-Induced Disorders Marijuana Abuse Mental Disorders Substance-Related Disorders

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Duke University Medical Center

Durham, North Carolina, 27706, United States

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Report 40 or more days of cannabis use (other than ingested cannabis, i.e., edibles) in past 90 days
  • Can speak and write fluent conversational English
  • Are between 18 and 80 years of age
  • Are willing to attempt to reduce frequency of cannabis use
  • Complete at least 10 of the 14 nightly diaries during the ad lib phase of the study procedures.

Exclusion criteria

  • Are expected to have an unstable medication regimen during the study
  • Are currently receiving non-study treatment for cannabis use disorder
  • Are pregnant or become pregnant
  • Meet criteria for a serious mental illness (e.g., bipolar disorder, schizophrenia)
  • Meet criteria for a substance use disorder other than nicotine or cannabis use disorders
  • Are currently imprisoned or in psychiatric hospitalization or become imprisoned or in psychiatric hospitalization
  • Report imminent risk for suicide or homicide
  • Meet criteria for bio-verified sustained abstinence (i.e., all of their saliva tests are negative during the 6-week experimental phase of the study)

Treatment and study plan

Mobile Contingency Management

Behavioral

Mobile contingency management is a mobile-phone based behavioral therapy that provides positive reinforcement (i.e., money) for abstinence that is highly effective at reducing substance use.

Other names: mCM

Primary outcomes

  1. Change in Mental Health Symptoms

    Time frame: Baseline and post-treatment (approximately eight weeks)

    Mental health symptoms will be measured by the 90-item Symptom Checklist (SCL-90). This measure has a scoring range of 0 to 360, with lower scores indicating lower distress related to mental health.

  2. Change in Self-reported Self-efficacy

    Time frame: Baseline and post-treatment (approximately eight weeks)

    Self-efficacy will be measured by the Marijuana Reduction Strategies Self-Efficacy Scale. This measure has a scoring range of 0 to 84, with higher scores indicating increased self-efficacy.

  3. Change in Physical Activity as Measured by the Leisure-Time Physical Activity Questionnaire

    Time frame: Baseline and post-treatment (approximately eight weeks)

    Physical activity will be measured using the Leisure-Time Physical Activity Questionnaire. Scores range from 0 to 99, with higher scores indicating increased physical activity.

  4. Change in Physical Activity as Measured by the International Physical Activity Questionnaire

    Time frame: Time Frame: Baseline and post-treatment (approximately eight weeks)

    Physical activity will be measured using a continuous score on the International Physical Activity Questionnaire. The score is calculated by multiplying metabolic equivalents times minutes per day times days per week; scores range from 0 to 13,440. Higher scores indicate increased physical activity.

Secondary outcomes

  1. Change in Health-related Quality of Life, WHOQOL-BREF

    Time frame: Baseline and post-treatment (approximately eight weeks)

    Health-related quality of life will be measured with the World Health Organization Quality of Life Brief (WHOQOL-BREF). The measure has a scoring range of 0 to 100, with higher scores indicating a higher quality of life.

  2. Change in Visual Working Memory

    Time frame: Baseline and post-treatment (approximately eight weeks)

    Visual working memory will be measured by the Visual Working Memory (VWM) Index of Wechsler Memory Scale, which is comprised of the Symbol Span and Spatial Addition subtests, whose scores are added together to create a VWM score. Although this scale has no minimum or maximum score, higher scores indicate better visual working memory.

  3. Change in Auditory Working Memory

    Time frame: Baseline and post-treatment (approximately eight weeks)

    Auditory working memory will be measured by the Auditory Working Memory (AWM) Index of Wechsler Memory Scale, which is comprised of the Digit Span and Letter-Number Sequencing subtests, whose scores are added together to create a AWM score. Although this scale has no minimum or maximum score, higher scores indicate better auditory working memory.

  4. Change in Impulsivity as Measured by Delay Discounting (i.e., Iowa Gambling Task)

    Time frame: Baseline and post-treatment (approximately eight weeks)

    Impulsivity will be measured with a delay discounting task called the Iowa Gambling Task. Scores range from -100 to 100. Higher scores indicate more advantageous choices (i.e., lower impulsivity).

  5. Change in Impulsivity as Measured by the Balloon Analogue Risk Task

    Time frame: Baseline and post-treatment (approximately eight weeks)

    Impulsivity will be measured with the Balloon Analogue Risk Task. Scores range from 0 to 128, and higher scores indicate higher impulsivity.

  6. Change in Impulsivity as Measured by Self-report

    Time frame: Baseline and post-treatment (approximately eight weeks)

    Self-reported impulsivity will be measured with the Urgency, Premeditation (lack of), Perserverance (lack of), Sensation Seeking, Positive Urgency, Impulsive Behavior Scale (UPPS-P). The measure has a score range of 59 to 236. Higher scores indicate higher impulsivity.

  7. Change in Number of Days of Drugged Driving

    Time frame: Baseline and post-treatment (approximately eight weeks)

    Number of days of drugged driving in the past month will be self-reported by participants using a Timeline Follow-Back Interview.

Sponsors and collaborators

Lead sponsor

Duke University

Other

Registry information

Acronym: FOCUS

Important dates

Study start
2021
Primary completion
2023
Study completion
2023
First posted
Sep 28, 2020
Registry last updated
Dec 24, 2024

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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