Is gabapentin an appropriate treatment for anxiety?

Is Gabapentin a Good Treatment for Anxiety?

No, gabapentin should not be used as a first-line treatment for anxiety and should only be considered when standard treatments have failed or are contraindicated, given the lack of robust evidence, significant safety concerns including dependence and withdrawal risks, and availability of superior alternatives.

First-Line Treatment Recommendations

SSRIs and SNRIs are the recommended first-line pharmacological treatments for anxiety disorders, with substantial evidence supporting their efficacy 1. These should be your initial pharmacological approach before considering gabapentin.

• Cognitive behavioral therapy (CBT) should be offered as first-line non-pharmacological treatment 1
• Benzodiazepines may be used only for short-term management of severe anxiety (not long-term) due to dependence risks 1

When Gabapentin Might Be Considered

Gabapentin may be considered only as a second-line option when first-line treatments have failed or are contraindicated 1. The Canadian Clinical Practice Guideline specifically lists gabapentin as a second-line drug for social anxiety disorder 1.

Specific scenarios where gabapentin may have utility:

• Preoperative anxiety: Both pregabalin and gabapentin show effectiveness in reducing preoperative anxiety (standardized mean difference -0.55 and -0.92 respectively) 2
• Breast cancer survivors with anxiety: A randomized controlled trial showed gabapentin 300-900 mg was significantly better than placebo at 4 and 8 weeks, with lower doses (300 mg) associated with best outcomes except in highest baseline anxiety 3
• Patients with comorbid conditions such as neuropathic pain, seizures, or hot flashes where gabapentin addresses multiple symptoms simultaneously 1, 3
• Patients with substance use history who cannot take benzodiazepines due to addiction risk 3

Critical Safety Concerns

The evidence reveals serious safety issues that must inform your prescribing decision:

• Dependence and withdrawal: Gabapentin carries significant risks of dependence and withdrawal symptoms, particularly with continuous use for 12+ months 1
• Mortality risk: Pregabalin deaths now exceed those from diazepam, fentanyl, tricyclics, or SSRIs as groups, with 244 deaths recorded in 2019 in England alone 4
• Respiratory depression: When combined with opioids, dangerous respiratory depression can occur, requiring heightened caution 1
• Common side effects: Monitor for sedation, dizziness, visual disturbances, and peripheral edema 1

Evidence Quality Assessment

The evidence base for gabapentin in anxiety is weak:

• No randomized controlled trials exist for generalized anxiety disorder 5
• A systematic review found only moderate evidence for anxiety states overall, with minimal evidence in other psychiatric conditions 2
• Controlled studies in bipolar disorder found gabapentin unhelpful 6
• Most psychiatric evidence comes from short-term trials with marginal differences from placebo, not accounting for long-term tolerance, dependence, and withdrawal 4

Practical Prescribing Algorithm

If you decide to use gabapentin after first-line failures:

1. Start with lowest effective dose: 300 mg was associated with best outcomes in the breast cancer trial except for highest baseline anxiety 3
2. Limit duration: Use perioperatively as single lowest preoperative dose when possible 1; avoid continuous use beyond 12 months 1
3. Adjust for special populations: Reduce dosing in elderly patients and those with renal dysfunction 1
4. Screen for opioid use: Absolutely avoid or use extreme caution in patients on concurrent opioid therapy 1
5. Plan discontinuation from the start: Offer careful tapering and support if discontinuation is planned after long-term use 1
6. Monitor treatment response: Evaluate regularly using standardized anxiety measures 1

Common Pitfalls to Avoid

• Do not use gabapentin as first-line therapy when SSRIs/SNRIs and CBT have superior evidence 1
• Do not prescribe long-term without clear justification given dependence risks and rising mortality data 4
• Do not combine with opioids without extreme caution and monitoring 1
• Do not assume efficacy in generalized anxiety disorder as no RCTs exist for this indication 5