Can gabapentin (anticonvulsant) be used to treat anxiety?

Gabapentin for Anxiety Treatment

Gabapentin is not recommended as a first-line treatment for anxiety disorders, but may be considered as a second-line option when first-line treatments have failed or are contraindicated. 1

Evidence-Based Treatment Hierarchy for Anxiety

• SSRIs and SNRIs are the recommended first-line pharmacological treatments for anxiety disorders with substantial evidence supporting their efficacy 1
• Cognitive behavioral therapy (CBT) is recommended as a first-line non-pharmacological treatment for anxiety disorders 1
• Benzodiazepines may be used for short-term management of severe anxiety but carry risks of dependence and are not recommended for long-term use 1
• Gabapentin may be considered when first-line treatments have failed or are contraindicated 1, 2

Clinical Evidence for Gabapentin in Anxiety

• Limited high-quality evidence exists for gabapentin's efficacy in generalized anxiety disorder, with most support coming from case reports rather than randomized controlled trials 3, 2
• A systematic review found that gabapentin may have benefit for some anxiety disorders, although there are no robust studies specifically for generalized anxiety disorder 2
• In a controlled trial with breast cancer survivors, gabapentin (300mg and 900mg) showed significant anxiolytic effects compared to placebo at both 4 and 8 weeks 4
• An experimental study demonstrated that gabapentin (800mg) attenuated anxiety in healthy volunteers during simulated public speaking 5

Specific Clinical Considerations

• The Canadian Clinical Practice Guideline lists gabapentin as a second-line drug for social anxiety disorder 6
• Lower doses (300mg) may be effective for most patients with mild to moderate anxiety, while higher doses may be needed for those with severe baseline anxiety 4
• Gabapentin may be particularly useful in patients with comorbid conditions that might benefit from its use, such as neuropathic pain, seizures, or insomnia 1
• For patients reluctant to take benzodiazepines or those with a history of substance use, gabapentin may offer an alternative therapy with lower abuse potential 4

Safety Concerns and Monitoring

• Gabapentinoids (including gabapentin) have been associated with tolerance, dependence, addiction, and withdrawal symptoms, similar to benzodiazepines 7
• In 2019, gabapentinoids were classified as controlled substances (Class C) in some countries due to these risks 7
• Deaths involving pregabalin (a related gabapentinoid) have been rising, particularly when used concomitantly with opioids or other drugs 7
• Regular evaluation of treatment response using standardized anxiety measures is recommended 1

Practical Prescribing Approach

• Start with lower doses (300mg daily) and titrate based on response and tolerability 4
• Monitor for side effects including somnolence, dizziness, and peripheral edema 2
• Evaluate efficacy after 4-8 weeks of treatment 4
• Consider discontinuation if no meaningful improvement is observed 7
• When discontinuing, taper gradually to minimize withdrawal symptoms 3

Limitations of Current Evidence

• Most studies on gabapentin for anxiety are short-term and don't account for long-term effects of tolerance and dependence 7
• Variation in dosing between studies makes it difficult to establish optimal dosing guidelines 2
• Studies vary in whether gabapentin is used as monotherapy or adjunctive treatment 2
• Different primary outcomes between trials complicate direct comparisons 2