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Completed

NCT Number: NCT03904498

COMT Inhibition Among Individuals With Comorbid AUD/ADHD

The purpose of this study is to determine whether the catechol-O-methyltransferase (COMT) inhibitor tolcapone, relative to placebo, affects response to alcohol, decision-making, brain activation associated with alcohol cue reactivity, response inhibition, and selective attention, or alcohol drinking.

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Key information

Conditions

Alcohol Use Disorder Alcohol-Related Disorders Alcoholism Attention Deficit Disorder with Hyperactivity Attention Deficit Hyperactivity Disorder Attention Deficit and Disruptive Behavior Disorders Chemically-Induced Disorders Mental Disorders Neurodevelopmental Disorders Substance-Related Disorders

Age range

21 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

University of Colorado Anschutz Medical Campus

Aurora, Colorado, 80045, United States

About this study

This study evaluates the effects of an FDA-approved medication called tolcapone in people who have both Alcohol Use Disorder (AUD) and Attention-Deficit/Hyperactivity Disorder (ADHD). The study involves seven visits over a three to four week period, including an assessment visit and two eight-day medication periods during which participants will be assigned to take, in a double-blinded fashion, both tolcapone and a placebo (three visits during each period). During two of these visits, participants will undergo a one-hour MRI scan. Participants must not be seeking treatment for AUD or ADHD and must not be currently taking any psychotropic medications, including stimulant medications for ADHD.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Age 21-65.
  • Meets Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) criteria for current Alcohol Use Disorder (AUD) and current Attention-Deficit/Hyperactivity Disorder (ADHD), as assessed by the Structured Clinical Interview for DSM-5 (SCID-5) or WHO-ASRS.
  • Currently not engaged in, and does not want treatment for, AUD or ADHD.
  • Currently not taking any medication for AUD or ADHD.
  • Able to read and understand questionnaires and informed consent.
  • Lives within 50 miles of the study site.

Exclusion criteria

  • Current DSM-5 diagnosis of any other substance use disorder except Nicotine Use Disorder.
  • Any psychoactive substance use (except nicotine) within the last 30 days, as indicated by self-report and urine drug screen (UDS)
  • Current DSM-5 psychotic, mood, anxiety, obsessive-compulsive, trauma-related, or eating disorder, as assessed by SCID-5.
  • Current suicidal ideation or homicidal ideation.
  • Current use of any psychoactive medication, as evidenced by self-report and UDS.
  • History of severe alcohol withdrawal (e.g., seizure, delirium tremens), as evidenced by self-report and assessment with Clinical Institute Withdrawal Assessment for Alcohol-Revised (CIWA-Ar).
  • Clinically significant medical problems such as cardiovascular, renal, gastrointestinal, or endocrine problems, as evidenced by medical history and physical exam.
  • Past alcohol-related medical illness, such as gastrointestinal bleeding, pancreatitis, or peptic ulcer.
  • Current or past hepatocellular disease, as indicated by verbal report, or elevations of alanine aminotransferase (ALT) or aspartate aminotransferase (AST) greater than the upper limit of the normal range at screening.
  • Females of childbearing potential who are pregnant (by plasma HCG), nursing, or who are not using a reliable form of contraception.
  • Current charges pending for a violent crime (not including DUI-related offenses).
  • Lack of a stable living situation.
  • Presence of ferrous metal in the body, as evidenced by metal screening and self-report.
  • Severe claustrophobia or morbid obesity that preclude placement in the MRI scanner.
  • History of neurological disease or head injury with > 2 minutes of unconsciousness.

Treatment and study plan

Tolcapone

Drug

Tolcapone 100 mg tablets

Other names: Tasmar

Placebo

Drug

Placebo tablets

Primary outcomes

  1. Change in alcohol-induced stimulation between medication periods

    Time frame: 30 minutes after laboratory alcohol administration on Day 1 of each medication period. Each medication period is 8 days long.

    Biphasic Alcohol Effects Scale stimulation score (range = 0-70; higher scores = more stimulation) after laboratory alcohol administration

  2. Change in subjective response to alcohol between medication periods

    Time frame: 30 minutes after laboratory alcohol administration on Day 1 of each medication period. Each medication period is 8 days long.

    Subjective High Assessment Scale (range - 0-130; higher scores = greater intoxication) after laboratory alcohol administration

  3. Change in risky decision-making after alcohol administration between medication periods

    Time frame: 30 minutes after laboratory alcohol administration on Day 1 of each medication period. Each medication period is 8 days long.

    Balloon Analogue Risk Task adjusted average number of pumps (higher scores = more risky decision-making)

  4. Change in cognitive-control-associated brain activation (fMRI) between medication periods

    Time frame: 60 minutes after medication ingestion on Day 2 of each medication period. Each medication period is 8 days long.

    Stop-signal task blood oxygenation level dependent (BOLD) signal to successful stop trials, relative to unsuccessful stop trials

  5. Change in selective attention-associated brain activation (fMRI) between medication periods

    Time frame: 60 minutes after medication ingestion on Day 2 of each medication period. Each medication period is 8 days long.

    Multi-source interference task BOLD signal to interference trials, relative to control trials

  6. Change in alcohol cue-elicited brain activation (fMRI) between medication periods

    Time frame: 60 minutes after medication ingestion on Day 2 of each medication period. Each medication period is 8 days long.

    Alcohol cue reactivity task BOLD signal to alcohol cues, relative to neutral beverage cues

Sponsors and collaborators

Lead sponsor

University of Colorado, Denver

Other

Collaborators

  • National Institute on Alcohol Abuse and Alcoholism (NIAAA)

Registry information

Official study title

COMT Inhibition as a Potential Therapeutic Target Among Individuals With Comorbid Alcohol Use Disorder and Attention-Deficit/Hyperactivity Disorder

Important dates

Study start
2021
Primary completion
2026
Study completion
2026
First posted
Apr 5, 2019
Registry last updated
May 4, 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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