Clinical trial NCT03334721: Gabapentin for Bipolar & Cannabis Use Disorders
Official title: Gabapentin for Bipolar & Cannabis Use Disorders
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE2
Conditions: Bipolar I Disorder
Bipolar II Disorder
Cannabis Use Disorder
Substance Use Disorders
Lead sponsor: Medical University of South Carolina
Sponsor class: OTHER
Collaborators: name: National Institute on Drug Abuse (NIDA)
First posted: 2017-11-07
Enrollment: 23
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

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.

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.

Eligibility criteria: 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.

Primary outcomes:
measure: Prefrontal GABA Concentrations Through Proton Magnetic Resonance Spectroscopy
timeFrame: Day 5 of each experimental condition
Secondary outcomes:
Other outcomes:
Locations:
city: Charleston
country: United States
facility: Medical University of South Carolina
state: South Carolina
Study officials:
affiliation: Medical University of South Carolina
name: James J Prisciandaro, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Prisciandaro JJ, Mellick W, Squeglia LM, Hix S, Arnold L, Tolliver BK. Results from a randomized, double-blind, placebo-controlled, crossover, multimodal-MRI pilot study of gabapentin for co-occurring bipolar and cannabis use disorders. Addict Biol. 2022 Jan;27(1):e13085. doi: 10.1111/adb.13085. Epub 2021 Aug 14.