Research Study 19-1658

Primary Objective

The overarching hypothesis of this proposal is that brexpiprazole (BREX) (2 or 4 mg/day), relative to placebo, will reduce alcohol consumption and modulate the neural substrates of moderate-severe Alcohol Use Disorder (AUD), and that genotype at a variable number tandem repeat polymorphism (VNTR) in the DAT1/SLC6A3 gene will predict BREX effects. Participants will be non-treatment-seeking Alcohol Use Disorder individuals, and will be prospectively randomized to medication on the basis of their DAT1 VNTR genotype. Since BREX affects both cortical and striatal neurophysiology, we will use functional magnetic resonance imaging (fMRI) to test its effects on cortical (right inferior frontal gyrus; rIFG) activation associated with response inhibition and on striatal activation elicited by alcohol cues, and will explore whether either of these measures mediates BREX effects on drinking in the natural environment vs. a bar-lab setting, which may reflect different aspects of lost control over drinking.

Is this Study for You?

Let's Get Started!


Few medications are currently Food & Drug Administration (FDA)-approved for the treatment of Alcohol Use Disorder (AUD), and those that are have, on average, modest effects on drinking. Precision medicine research has explored whether patient-level variables, such as genetic variation, may identify subgroups of individuals with larger medication effects, but few findings have been replicated. A promising novel medication for AUD is brexpiprazole (BREX), a serotonin/dopamine activity modulator (SDAM). This study will evaluate the effects of two doses of BREX, relative to placebo, among non-treatment-seeking individuals with AUD, and will test whether DAT1 genotype influences these effects. Functional magnetic resonance imaging (fMRI) will be used to explore whether BREX effects on brain activation associated with cognitive control or elicited by alcohol cues accounts for its effects on drinking. If the study hypotheses are supported, BREX may represent a novel pharmacogenetic treatment for AUD.




Age 21-65 not currently seeking or engaged in treatment for Alcohol Use Disorder (AUD).

Please contact the Translational Addiction Imaging Laboratory (TrAIL Lab) at for more information about the study and additional eligibility criteria.

Type of Study





Department Specific Free Standing Clinic
Outpatient CTRC
University of Colorado Hospital

Principal Investigator
Photograph of Joseph Schacht,  PhD

Joseph Schacht, PhD

Study ID

Protocol Number: 19-1658

More information available at NCT04066192

Is this Study for You?

Let's Get Started!

Not finding the right Study for you? Join ResearchMatch, a nation-wide registry connecting volunteers and researchers