Gabapentin for Restoring GABA/Glutamate Homeostasis in Co-occurring Bipolar and Cannabis Use Disorders

• Sponsor: Medical University of South Carolina (Other)
• Overall Status: Recruiting
• CT.gov ID: NCT05064319
• Collaborator: National Institute on Drug Abuse (NIDA) (NIH)
• Enrollment: 68
• Location: 1
• Arms: 2
• Anticipated Duration (Months): 52.1
• Patients Per Site Per Month: 1.3

Study Details

Study Description

Brief Summary

This research study evaluates the effects of an FDA-approved medication Gabapentin in individuals with Bipolar Disorder who smoke marijuana. Participants in the study will will be assigned to take either Gabapentin or a matched placebo. Study medication will be taken for 17 days. There will be 5 study visits, with 2 MRI brain imaging scans completed. Questionnaires and clinical interview measures will be completed at study visits along with consistent assessment of potential side effects from study medication.

Condition or Disease	Intervention/Treatment	Phase
Bipolar Disorder; Cannabis Use; Schizoaffective Disorder, Bipolar Type; Bipolar I Disorder; Bipolar II Disorder; Cannabis Use Disorder, Mild; Cannabis Use Disorder, Moderate; Cannabis Use Disorder, Severe	Drug: Gabapentin; Drug: Placebo	Phase 2

Study Design

• Study Type: Interventional
• Anticipated Enrollment: 68 participants
• Allocation: Randomized
• Intervention Model: Parallel Assignment
• Masking: Triple (Participant, Care Provider, Investigator)
• Primary Purpose: Treatment
• Official Title: Gabapentin for Restoring GABA/Glutamate Homeostasis in Co-occurring Bipolar and Cannabis Use Disorders: A Randomized, Double-blind, Placebo-controlled, Parallel-group, MRI Study
• Actual Study Start Date: Feb 24, 2022
• Anticipated Primary Completion Date: Jun 30, 2026
• Anticipated Study Completion Date: Jun 30, 2026

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Group A - Gabapentin	Drug: Gabapentin; After group assignment but before taking any study medication, and again 17 days later, participants will have a Magnetic Resonance Imaging (MRI) exam after completing various assessments (clinical interview, questionnaires, etc.). Group A will receive gabapentin 2-3 times a day for a total of 17 days.
Placebo Comparator: Group B - Placebo	Drug: Placebo; After group assignment but before taking any study medication, and again 17 days later, participants will have a Magnetic Resonance Imaging (MRI) exam after completing various assessments (clinical interview, questionnaires, etc.). Group A will receive placebo 2-3 times a day for a total of 17 days.

Outcome Measures

Primary Outcome Measures

1. Change in prefrontal GABA concentrations through Proton Magnetic Resonance Spectroscopy [Baseline to end of treatment, approximately 17 days]

   Concentrations of GABA, normalized to water and corrected for CSF%, in dorsal anterior cingulate measured via Proton Magnetic Resonance Spectroscopy.

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years to 65 Years
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

Inclusion Criteria:

1. Ages 18-65 years

2. Meet DSM-5 criteria for moderate or severe cannabis use disorder (CUD; within the past 3 months), provide a positive urine cannabinoid screen at baseline, and identify cannabis as the primary substance of abuse

3. Meet DSM-5 criteria for bipolar I or II disorder (BD) or Schizoaffective Disorder, Bipolar Type

4. Able to provide informed consent and read, understand, and accurately complete assessment instruments

5. Willing to commit to medication treatment and follow-up assessments

6. Prescribed daily use of at least one mood stabilizing medication (i.e., lithium, divalproex sodium, lamotrigine, carbamazepine, 2nd generation antipsychotic)

Exclusion Criteria:

1. A primary psychiatric diagnosis other than BD (e.g., Schizophrenia)

2. Meet DSM-5 criteria for moderate or severe substance use disorder (other than cannabis or tobacco) within the past 60 days

3. Any uncontrolled neurological condition (e.g., epilepsy) that could confound the results of the study

4. Any history of brain injury with loss of consciousness greater than 5 minutes

5. Any history of mental retardation, dementia, or recent electroconvulsive therapy (in the past 3 months)

6. Any uncontrolled medical condition that may adversely affect the conduct of the study or jeopardize the safety of the participant

7. Hepatocellular disease as indicated by plasma levels of liver transaminases (aspartate transaminase, alanine transaminase) greater than 3 times the normal range

8. Renal insufficiency as indicated by plasma levels of creatinine greater than 2 times the normal range

9. Concomitant use of medications that could interfere with glutamatergic/GABAergic transmission (e.g., benzodiazepines, ceftriaxone, riluzole, memantine, ketamine, topiramate, vigabatrin), due to potential confounding effects

10. Concomitant use of opioid medications, benzodiazepines, barbiturates, chloral hydrate, sodium oxybate, or any other medication deemed to be hazardous if taken with gabapentin

11. Azelastine, orphenadrine, oxomemazine, paraldehyde, and thalidomide are generally contraindicated in patients taking gabapentin; as such, individuals taking these medications will be excluded

12. Women of childbearing potential who are pregnant, lactating, or refuse adequate forms of contraception

13. Current suicidal or homicidal risk

14. Baseline scores greater than 35 on the Montgomery-Asberg Depression Rating Scale or greater than 25 on the Young Mania Rating Scale

15. Has taken gabapentin in the last month or experienced adverse effects/allergic reaction (e.g., angioedema) from it at any time

16. Significant claustrophobia and/or past negative experiences with MRI

17. Presence of non-MRI safe materials in the body (e.g., ferrous metal implants, pacemaker)

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	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)

Investigators

• Principal Investigator: James J Prisciandaro, PhD, Medical University of South Carolina

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

• Responsible Party: James J. Prisciandaro, Associate Professor, Medical University of South Carolina
• ClinicalTrials.gov Identifier: NCT05064319
• Other Study ID Numbers: 00112593; R01DA054275
• First Posted: Oct 1, 2021
• Last Update Posted: Jul 8, 2022
• Last Verified: Jul 1, 2022

• Individual Participant Data (IPD) Sharing Statement: No
• Plan to Share IPD: No
• 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: Disease; Marijuana Abuse; Bipolar Disorder; Psychotic Disorders; Gabapentin

Study Results

No Results Posted as of Jul 8, 2022