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Gabapentin for Bipolar & Cannabis Use Disorders

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03334721
Recruitment Status : Completed
First Posted : November 7, 2017
Last Update Posted : July 31, 2019
National Institute on Drug Abuse (NIDA)
Information provided by (Responsible Party):
James J. Prisciandaro, Medical University of South Carolina

Brief Summary:
The proposed 2-week, double-blind, crossover, proof of concept study aims to measure and manipulate core neurochemical (i.e., dysregulated brain GABA/glutamate homeostasis) and neurobehavioral (i.e., elevated impulsivity) dysfunctions characteristic of individuals with cannabis use disorder (CUD) and Bipolar Disorder (BD), using a medication that has been shown to increase cortical GABA (i.e., gabapentin) levels in past research, and to evaluate medication-related changes in response inhibition (go no-go) and cannabis cue reactivity functional Magnetic Resonance Imaging tasks, as well as cannabis use, mood symptoms (including anxiety and sleep), and impulsivity in individuals with CUD+BD.

Condition or disease Intervention/treatment Phase
Bipolar I Disorder Bipolar II Disorder Cannabis Use Disorder Substance Use Disorders Drug: Gabapentin Drug: Placebo Oral Capsule Phase 2

Detailed Description:
Bipolar disorder (BD) is the Axis I condition most strongly associated with cannabis use disorder (CUD); there is a six-fold increase in the prevalence of CUD in individuals with BD relative to the general population. Individuals with co-occurring CUD and BD (CUD+BD) have substantially worse clinical outcomes than those with either BD or CUD alone. Response to mood stabilizing medications appears to be poor, yet little is known about optimal treatment for CUD+BD, as there have been no randomized medication trials for CUD+BD to date. Convergent evidence supports dysregulated brain γ-Aminobutyric acid (GABA)/glutamate homeostasis as a candidate target for pharmacological intervention in CUD+BD. Preclinical and clinical studies have demonstrated that CUD and BD are each associated with prefrontal GABA and glutamate disturbances and that impulsivity, a core neurobehavioral feature of both CUD and BD and a key Research Domain Criteria (RDoC) construct, is causally related to GABAergic/glutamatergic functioning. Gabapentin has been consistently shown in preclinical research to modulate GABA and glutamate transmission. In human Proton Magnetic Resonance Spectroscopy (1H-MRS) studies, both acute and chronic gabapentin dosing have been shown to increase brain GABA levels, however, few studies have investigated gabapentin effects on glutamate levels. Researchers propose that gabapentin may impact clinical outcomes in CUD+BD individuals both directly and indirectly through their impact on impulsivity.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 23 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Official Title: Gabapentin for Bipolar & Cannabis Use Disorders
Actual Study Start Date : October 1, 2017
Actual Primary Completion Date : July 1, 2019
Actual Study Completion Date : July 1, 2019

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Marijuana

Arm Intervention/treatment
Experimental: Gabapentin
Each 1-week condition will consist of an in-person study visit for assessment and dispensing of medication (Day 1), titration to maximum dose (i.e., 1,200mg gabapentin) (Days 1-5), MRI (Day 5), and medication washout (Days 5-7).
Drug: Gabapentin
5 day trial of gabapentin with titration to 1,200mg

Placebo Comparator: Placebo Oral Capsule
Each 1-week condition will consist of an in-person study visit for assessment and dispensing of medication (Day 1), titration to maximum dose (Days 1-5), MRI (Day 5), and medication washout (Days 5-7).
Drug: Placebo Oral Capsule
5 day trial of matched placebo

Primary Outcome Measures :
  1. Prefrontal GABA and glutamate concentrations through Spectroscopy [ Time Frame: Day 5 of each experimental condition ]
    Concentrations of GABA and glutamate in dorsal anterior cingulate measured via Proton Magnetic Resonance Spectroscopy.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Meets DSM-V criteria for Bipolar Disorder
  • Meets DSM-V criteria for Cannabis Use Disorder
  • Using at least one mood stabilizing medication

Exclusion Criteria:

  • Serious medical or non-inclusionary psychiatric disease
  • Concomitant use of benzodiazepine medications or any medications hazardous if taken with gabapentin
  • History of clinically significant brain injury
  • Presence of non-MRI safe material, or clinically significant claustrophobia.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03334721

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United States, South Carolina
Medical University of South Carolina
Charleston, South Carolina, United States, 29425
Sponsors and Collaborators
Medical University of South Carolina
National Institute on Drug Abuse (NIDA)
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Principal Investigator: James J Prisciandaro, PhD Medical University of South Carolina
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Responsible Party: James J. Prisciandaro, Assistant Professor, Medical University of South Carolina Identifier: NCT03334721    
Other Study ID Numbers: 69905
R21DA04391701A1 ( Other Grant/Funding Number: NIDA )
First Posted: November 7, 2017    Key Record Dates
Last Update Posted: July 31, 2019
Last Verified: July 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Product Manufactured in and Exported from the U.S.: No
Additional relevant MeSH terms:
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Marijuana Abuse
Substance-Related Disorders
Pathologic Processes
Chemically-Induced Disorders
Mental Disorders
Sensory System Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Anti-Anxiety Agents
Tranquilizing Agents
Central Nervous System Depressants
Psychotropic Drugs
Excitatory Amino Acid Antagonists
Excitatory Amino Acid Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Antimanic Agents