Can gabapentin, which the patient is taking for essential tremor, be used to treat their anxiety?

Gabapentin for Anxiety: Limited Evidence and Important Safety Concerns

Gabapentin is not a first-line treatment for anxiety disorders and should not be routinely used for this indication in your patient with essential tremor. While the Canadian guidelines list gabapentin as a second-line option specifically for social anxiety disorder 1, the FDA label does not include anxiety as an approved indication, and importantly, antiepileptic drugs including gabapentin increase the risk of suicidal thoughts and behavior 2.

Key Evidence and Reasoning

Guideline Recommendations for Anxiety

The 2023 Japanese Society guidelines on social anxiety disorder position gabapentin as follows 1:

• First-line agents: SSRIs (escitalopram, fluvoxamine, paroxetine, sertraline), SNRI (venlafaxine), and pregabalin
• Second-line agents: Benzodiazepines and gabapentin (per Canadian CPG)
• Notably, gabapentin is listed as second-line only in the Canadian guidelines, while other major guidelines (NICE, S3) do not recommend it at all

Critical FDA Safety Warnings

The FDA label contains several warnings directly relevant to anxiety treatment 2:

• Doubled risk of suicidal ideation: AEDs including gabapentin increase suicidal thoughts/behavior (Relative Risk 1.8,95% CI: 1.2-2.7)
• Risk appears as early as one week and persists throughout treatment
• For psychiatric indications specifically: 8.5 events per 1000 patients vs 5.7 per 1000 on placebo
• CNS depression: 19-21% experience somnolence, 17-28% experience dizziness
• These sedative effects may worsen anxiety symptoms or be mistaken for anxiety improvement

Research Evidence is Weak

The available research shows inconsistent results:

• A 2000 placebo-controlled trial in panic disorder found no overall benefit (p=0.606), with only post-hoc analysis suggesting possible benefit in severely ill patients 3
• Only case reports exist for generalized anxiety disorder 4
• No randomized controlled trials exist for GAD specifically 4

For Essential Tremor Context

Your patient is already taking gabapentin for essential tremor. Recent evidence shows:

• A 2025 meta-analysis found gabapentin did not significantly outperform placebo in between-group comparisons for ET 5
• Within-group analysis showed some tremor reduction with gabapentin (but not pregabalin) 5
• Gabapentin monotherapy is considered "probably effective" for ET, though evidence is limited 6, 7

Clinical Approach

If your patient has anxiety while on gabapentin for essential tremor:

1. Do not increase gabapentin dose for anxiety treatment—this is off-label use with weak evidence and significant risks
2. Consider evidence-based anxiety treatments instead:
   • SSRIs (escitalopram, sertraline) as first-line pharmacotherapy
   • CBT if available
   • SNRIs (venlafaxine) as alternative
3. Monitor closely for:
   • Worsening depression or suicidal ideation (especially in first weeks)
   • Excessive sedation or dizziness that may impair function
   • Whether anxiety symptoms might actually be related to gabapentin's CNS effects

Important Caveats

• The sedative properties of gabapentin (somnolence in 19-21% of patients) may be confused with anxiolytic effects 2
• If anxiety emerged after starting gabapentin, consider whether it represents a neuropsychiatric adverse reaction rather than a separate condition requiring additional treatment
• The lack of FDA approval for anxiety disorders reflects the absence of robust efficacy data
• Any perceived benefit in individual patients must be weighed against the documented increased suicide risk in patients taking AEDs for psychiatric indications

Bottom line: Treat the anxiety with evidence-based first-line agents (SSRIs/SNRIs or CBT) rather than relying on or increasing gabapentin, which lacks strong efficacy data for anxiety and carries significant psychiatric safety risks.