Gabapentin for Bipolar Disorder

Overseen By James J Prisciandaro, PhD

Age: 18+

Sex: Any

Trial Phase: Phase 2

Sponsor: Medical University of South Carolina

Must be taking: Mood stabilizers

Must not be taking: Benzodiazepines, Opioids, Barbiturates, others

Disqualifiers: Schizophrenia, Epilepsy, Brain injury, others

Prior Safety Data This treatment has passed at least one previous human trial

Compensation: Varies

Number of Visits: 5

Duration: 2.5 weeks

68 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to explore how Gabapentin, an FDA-approved medication, can help people with Bipolar Disorder who also use marijuana. Participants will take either Gabapentin or a placebo for 17 days to assess the medication's effectiveness. The study includes five visits, with two MRI brain scans and check-ups to monitor side effects. Ideal candidates are those diagnosed with Bipolar Disorder, who regularly use marijuana, and are already on mood-stabilizing medications. As a Phase 2 trial, this research measures Gabapentin's effectiveness in an initial, smaller group, offering participants a chance to contribute to important findings.

Will I have to stop taking my current medications?

The trial requires participants to be on a daily mood stabilizing medication, but you cannot take certain medications that interfere with gabapentin, like benzodiazepines or opioids. If you're on any of these, you might need to stop them to join the trial.

Is there any evidence suggesting that Gabapentin is likely to be safe for humans?

Research generally considers gabapentin safe for humans. The FDA has approved it for treating conditions like epilepsy and nerve pain. Studies have shown that many people tolerate gabapentin well. For instance, one study found that 88% of patients completed their treatment without major issues. Another study described gabapentin as relatively safe overall.

However, like any medication, gabapentin can have side effects. Some users reported an increased risk of depression. It's important to weigh these potential side effects against the benefits. Prospective clinical trial participants should discuss any concerns with a healthcare provider. This discussion can help determine if gabapentin is a safe choice. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising for Bipolar Disorder?

Gabapentin is unique because it's traditionally used for nerve pain and seizures, but researchers are exploring its potential for treating bipolar disorder. Unlike the standard treatments for bipolar disorder, which often include mood stabilizers like lithium or antipsychotics, gabapentin works through a different mechanism by affecting calcium channels in the brain. This could offer a new approach for patients who don't respond well to current medications. Researchers are excited about gabapentin's potential to provide a new option with possibly fewer side effects or interactions compared to traditional bipolar medications.

What evidence suggests that Gabapentin might be an effective treatment for Bipolar Disorder?

Research has shown that gabapentin might not be very effective for treating bipolar disorder. One study found that gabapentin was less effective than a placebo for managing manic episodes, suggesting it may not work well for this condition. Another study found that while gabapentin might help with symptoms like irritability and anxiety, it doesn't significantly improve depression in bipolar disorder. Current treatment guidelines do not recommend gabapentin for bipolar disorder due to a lack of clear benefits. This trial will compare gabapentin, administered to participants in Group A, with a placebo, given to participants in Group B, to further evaluate its effectiveness for bipolar disorder. While gabapentin might help with some symptoms, it is generally not advised for treating bipolar disorder. ^{1 2 6 7 8}

Who Is on the Research Team?

James J Prisciandaro, PhD

Principal Investigator

Medical University of South Carolina

Are You a Good Fit for This Trial?

Adults aged 18-65 with bipolar disorder and moderate to severe cannabis use disorder, who are already on mood stabilizers, can join this study. They must be willing to take medication and attend follow-ups. Exclusions include certain medical conditions, recent electroconvulsive therapy, pregnancy or inadequate contraception use, high risk of suicide or homicide, past negative reactions to gabapentin or MRI scans.

Inclusion Criteria

I take a daily mood stabilizer like lithium or lamotrigine.

I have a significant problem with cannabis use, tested positive for it, and it's my main substance issue.

I am willing to follow the treatment and check-up plan.

Exclusion Criteria

I am not pregnant, breastfeeding, and I use effective birth control.

My kidney function is low, with creatinine levels more than double the normal range.

I am not taking opioids, benzodiazepines, barbiturates, or similar medications.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive either Gabapentin or a matched placebo for 17 days. Study visits include MRI brain imaging scans, questionnaires, and clinical interviews.

2.5 weeks

5 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Gabapentin
• Placebo

Trial Overview The trial is testing Gabapentin against a placebo in people with bipolar disorder who also smoke marijuana. Over 17 days, participants will take the assigned treatment and undergo brain scans (MRI), questionnaires, interviews, and side effect monitoring during five visits.

How Is the Trial Designed?

Group I: Group A - Gabapentin Experimental Treatment 1 Intervention

Group II: Group B - Placebo Placebo Group 1 Intervention

Gabapentin is already approved in United States, European Union, Canada for the following indications:

Approved in United States as Neurontin for:

• Postherpetic neuralgia
• Partial-onset seizures

Approved in European Union as Gabapentin for:

• Peripheral neuropathic pain
• Partial-onset seizures

Approved in Canada as Gabapentin for:

• Postherpetic neuralgia
• Partial-onset seizures

Who Is Running the Clinical Trial?

Medical University of South Carolina

Lead Sponsor

Trials

994

Recruited

7,408,000+

National Institute on Drug Abuse (NIDA)

Collaborator

Trials

2,658

Recruited

3,409,000+

Published Research Related to This Trial

In a study of 28 bipolar patients, gabapentin showed a positive response rate of 78% for those experiencing manic symptoms, with the fastest response seen in patients with hypomania (average 12.7 days).

Gabapentin was well tolerated, with sedation being the most common side effect, suggesting it could be a safe adjunctive treatment for refractory bipolar disorder, although further double-blind studies are needed to confirm its efficacy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Gabapentin in the acute treatment of refractory bipolar disorder. Altshuler, LL., Keck, PE., McElroy, SL., et al.[2019]

In a study of seven severe bipolar patients who could not use traditional mood stabilizers, gabapentin was administered for a median of 9 months, showing improvements in irritability and dysphoria for all patients.

However, the monthly relapse rate increased from 0.18 to 0.29 during gabapentin treatment, suggesting that while it may help with some symptoms, its overall effectiveness in preventing relapses needs further investigation through clinical trials.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Efficacy of gabapentin in a sample of bipolar patients]. Montañés Rada, F., de Lucas Taracena, MT.[2018]

Gabapentin, an anticonvulsant with a good safety profile, was successfully used to treat a 12-year-old boy with bipolar disorder II and ADHD, showing significant mood stabilization within 3 weeks and maintained improvement over 6 months.

Despite promising results in this case, there is a lack of controlled studies on gabapentin's efficacy for bipolar disorder in children and adolescents, highlighting the need for further research to explore its potential mood-stabilizing properties.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Gabapentin and methylphenidate treatment of a preadolescent with attention deficit hyperactivity disorder and bipolar disorder. Hamrin, V., Bailey, K.[2018]

Gabapentin has been reviewed for its effectiveness in treating bipolar disorder, but the evidence suggests it is not a suitable treatment option.

Further research is needed to explore any potential role gabapentin may have in managing bipolar disorder, as current data does not support its use.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Gabapentin treatment for bipolar disorders. Maidment, ID.[2018]

In a double-blind, placebo-controlled trial involving patients with bipolar disorder, gabapentin did not show significant efficacy as an adjunctive treatment compared to placebo, with a smaller reduction in mania symptoms as measured by the Young Mania Rating Scale (YMRS).

The study indicated that more patients in the placebo group had adjustments made to their ongoing lithium therapy, suggesting that gabapentin may not be effective in managing bipolar disorder symptoms when added to standard treatments.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Gabapentin in bipolar disorder: a placebo-controlled trial of adjunctive therapy. Gabapentin Bipolar Disorder Study Group. Pande, AC., Crockatt, JG., Janney, CA., et al.[2019]

A literature review identified 29 studies on gabapentin for bipolar disorder, but most were of poor quality, including 15 uncontrolled case series and only 4 small randomized trials showing little evidence of efficacy.

Despite the lack of strong clinical evidence, the high volume of publications may have created a misleading perception of gabapentin's effectiveness, contributing to its widespread use in treating bipolar disorder.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Gabapentin in the treatment of mental illness: the echo chamber of the case series. Carey, TS., Williams, JW., Oldham, JM., et al.[2018]

In a 1-year randomized controlled trial involving 25 euthymic bipolar disorder patients, gabapentin showed a statistically significant improvement in the Clinical Global Impressions scale for Bipolar Illness compared to placebo, indicating potential long-term benefits for managing bipolar disorder.

Gabapentin was well tolerated with no emergence of manic or depressive symptoms, suggesting it may be a safe adjunctive treatment option for patients already on mood stabilizers.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A double-blind, randomized, placebo-controlled, prophylaxis study of adjunctive gabapentin for bipolar disorder. Vieta, E., Manuel Goikolea, J., Martínez-Arán, A., et al.[2019]

Gabapentin showed moderate effectiveness in treating depressive symptoms in patients with non-refractory bipolar disorder, with a 27.6% overall improvement in depression and a 57.5% improvement in a subgroup of depressed patients.

While gabapentin did not induce mania and was well-tolerated by most, 62% of patients experienced side effects, primarily sedation and nausea, leading to a 14% discontinuation rate due to adverse events.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Gabapentin treatment of the non-refractory bipolar spectrum: an open case series. Ghaemi, SN., Goodwin, FK.[2019]

In a 12-week open trial with 22 patients suffering from bipolar depression, gabapentin (GBP) significantly reduced depression scores by 53%, indicating its potential effectiveness as an adjunctive treatment.

GBP was well tolerated among participants, with 55% showing moderate to marked improvement, particularly in those with mild to moderate depression, suggesting it may be a beneficial option for this subgroup.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Gabapentin augmentation therapy in bipolar depression. Wang, PW., Santosa, C., Schumacher, M., et al.[2019]

Gabapentin shows promise as a treatment for various psychiatric disorders, including bipolar disorder and anxiety, due to its favorable side effect profile and minimal drug interactions, but there is a lack of robust studies to confirm its efficacy as a standalone treatment.

Current evidence is limited to case reports and small studies, indicating that while gabapentin may be beneficial as an adjunct therapy, more well-designed research is needed to establish its effectiveness in treating bipolar disorder and anxiety disorders.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Gabapentin: a review of published experience in the treatment of bipolar disorder and other psychiatric conditions. Letterman, L., Markowitz, JS.[2019]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9095464/

Gabapentin and pregabalin in bipolar disorder, anxiety states ... Gabapentin showed a significantly greater improvement on the depression symptoms subscale (50%) compared to lamotrigine (33.5%) and carbamazepine (13.6%). There ...

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC4879613/

The rise and fall of gabapentin for bipolar disorder In fact, one study showed gabapentin to be inferior to placebo in the treatment of bipolar mania (20). The clear evidence that emerged regarding the lack of ...

3. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0006322397003053

Acute Treatment of Bipolar Depression with Gabapentin Gabapentin (Andrews and Fischer 1994) has been suggested to have mood-stabilizing and possibly antidepressant properties in bipolar disorder.

4. mdpi.com mdpi.com/1424-8247/14/9/834

A Systematic Review of the Clinical Use of Gabapentin and ... Gabapentin and pregabalin are probably not effective for depressive state but may improve some subscales, such as irritability, social withdrawal or anxiety.

5. pcl.psychiatry.uw.edu pcl.psychiatry.uw.edu/lack-of-evidence-gabapentin-in-bipolar-disorder/

Lack of Evidence: Gabapentin in Bipolar Disorder Gabapentin does not demonstrate efficacy in randomized trials for bipolar disorder and current treatment guidelines do not emphasize its use.

6. journals.lww.com journals.lww.com/md-journal/fulltext/2025/08220/correlation_between_gabapentin_and_depression__a.94.aspx

Correlation between gabapentin and depression: A study ... Our analysis revealed that gabapentin users had a higher risk of depression. In a multivariate logistic regression model, the odds ratio was 1.8 ...

7. psychiatrist.com psychiatrist.com/jcp/clinical-experience-gabapentin-patients-bipolar-schizoaffective/

Clinical Experience With Gabapentin in Patients ... Results:Twenty-two patients (88%) completed the 16 weeks of treatment with gabapentin; 19 (76%) had a positive response as measured by changes ...

8. jdc.jefferson.edu jdc.jefferson.edu/cgi/viewcontent.cgi?article=1405&context=jeffjpsychiatry

Gabapentin in the Treatment of Bipolar Disorder Further study is needed to determine if gabapent in has inherent antidepres- sa nt effec ts. SAFETY. Gabapentin has proven itself to be a relatively safe drug.