Question 1

Is ketamine or esketamine an option for my patient with severe treatment-resistant anxiety?

Accepted Answer

Ketamine (NMDA receptor antagonist) produces rapid anxiolytic effects via NMDA blockade on GABAergic interneurons, disinhibiting pyramidal neurons, producing a glutamate surge that activates AMPA receptors, triggering BDNF-TrkB signaling and mTOR-driven synaptogenesis. Taylor 2018 RCT (social anxiety, N=18): single 0.5mg/kg IV ketamine — 33% response within 2 weeks vs. 0% placebo. Hartland 2023 meta-analysis: significant anxiolytic effects within 12 hours, sustained 1-2 weeks. Glue 2017/2020: dose-related effects in TR-GAD/SAD. Meisner 2025 (TRD population, not anxiety-specific): IV ketamine faster initial relief (49.2% reduction) vs. esketamine (40%). NNH=2 for adverse events. Esketamine (Spravato) FDA-approved depression only, no anxiety indication; requires in-clinic administration/monitoring. Durability is fundamental limitation — effects wane within days to weeks without repeated infusions. Stage 3 MTR-AD positioning only, under specialist supervision.

Question 2

What's the evidence for ketamine in anxiety specifically?

Accepted Answer

Ketamine (NMDA receptor antagonist) produces rapid anxiolytic effects via NMDA blockade on GABAergic interneurons, disinhibiting pyramidal neurons, producing a glutamate surge that activates AMPA receptors, triggering BDNF-TrkB signaling and mTOR-driven synaptogenesis. Taylor 2018 RCT (social anxiety, N=18): single 0.5mg/kg IV ketamine — 33% response within 2 weeks vs. 0% placebo. Hartland 2023 meta-analysis: significant anxiolytic effects within 12 hours, sustained 1-2 weeks. Glue 2017/2020: dose-related effects in TR-GAD/SAD. Meisner 2025 (TRD population, not anxiety-specific): IV ketamine faster initial relief (49.2% reduction) vs. esketamine (40%). NNH=2 for adverse events. Esketamine (Spravato) FDA-approved depression only, no anxiety indication; requires in-clinic administration/monitoring. Durability is fundamental limitation — effects wane within days to weeks without repeated infusions. Stage 3 MTR-AD positioning only, under specialist supervision.

Question 3

How fast is the onset compared to SSRIs?

Accepted Answer

Ketamine (NMDA receptor antagonist) produces rapid anxiolytic effects via NMDA blockade on GABAergic interneurons, disinhibiting pyramidal neurons, producing a glutamate surge that activates AMPA receptors, triggering BDNF-TrkB signaling and mTOR-driven synaptogenesis. Taylor 2018 RCT (social anxiety, N=18): single 0.5mg/kg IV ketamine — 33% response within 2 weeks vs. 0% placebo. Hartland 2023 meta-analysis: significant anxiolytic effects within 12 hours, sustained 1-2 weeks. Glue 2017/2020: dose-related effects in TR-GAD/SAD. Meisner 2025 (TRD population, not anxiety-specific): IV ketamine faster initial relief (49.2% reduction) vs. esketamine (40%). NNH=2 for adverse events. Esketamine (Spravato) FDA-approved depression only, no anxiety indication; requires in-clinic administration/monitoring. Durability is fundamental limitation — effects wane within days to weeks without repeated infusions. Stage 3 MTR-AD positioning only, under specialist supervision.

Question 4

What are the dissociation and abuse risks?

Accepted Answer

Ketamine (NMDA receptor antagonist) produces rapid anxiolytic effects via NMDA blockade on GABAergic interneurons, disinhibiting pyramidal neurons, producing a glutamate surge that activates AMPA receptors, triggering BDNF-TrkB signaling and mTOR-driven synaptogenesis. Taylor 2018 RCT (social anxiety, N=18): single 0.5mg/kg IV ketamine — 33% response within 2 weeks vs. 0% placebo. Hartland 2023 meta-analysis: significant anxiolytic effects within 12 hours, sustained 1-2 weeks. Glue 2017/2020: dose-related effects in TR-GAD/SAD. Meisner 2025 (TRD population, not anxiety-specific): IV ketamine faster initial relief (49.2% reduction) vs. esketamine (40%). NNH=2 for adverse events. Esketamine (Spravato) FDA-approved depression only, no anxiety indication; requires in-clinic administration/monitoring. Durability is fundamental limitation — effects wane within days to weeks without repeated infusions. Stage 3 MTR-AD positioning only, under specialist supervision.

PsychHQ

Ketamine and Esketamine for Treatment-Resistant Anxiety: Promise and Limitation