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

Bipolar Disorder Clinical Trial

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

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05064319
• Other study ID #: 00112593
• Secondary ID: R01DA054275
• Status: Recruiting
• Phase: Phase 2
• Start date: February 24, 2022
• Est. completion date: June 30, 2026

Study information

• Verified date: July 2023
• Source: Medical University of South Carolina
• Contact: Sara Hix
• Phone: 843-792-7500
• Email: hixs[@]musc.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 68
• Est. completion date: June 30, 2026
• Est. primary completion date: June 30, 2026
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 65 Years

Eligibility

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)

Related Conditions & MeSH terms

• Bipolar Disorder
• Bipolar I Disorder
• Bipolar II Disorder
• Cannabis Use
• Cannabis Use Disorder, Mild
• Cannabis Use Disorder, Moderate
• Cannabis Use Disorder, Severe
• Marijuana Abuse
• Psychotic Disorders

Intervention

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
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.

Locations

Country	Name	City	State
United States	Medical University Of South Carolina	Charleston	South Carolina

Sponsors (2)

Lead Sponsor	Collaborator
Medical University of South Carolina	National Institute on Drug Abuse (NIDA)

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in prefrontal GABA concentrations through Proton Magnetic Resonance Spectroscopy	Concentrations of GABA, normalized to water and corrected for CSF%, in dorsal anterior cingulate measured via Proton Magnetic Resonance Spectroscopy.	Baseline to end of treatment, approximately 17 days