Ketamine for post-traumatic stress disorder is off-label, emerging-evidence medicine. There is real peer-reviewed data — particularly the Feder 2014 single-dose and Feder 2021 repeated-dose RCTs at Mount Sinai — but the effect sizes in pooled analyses are modest, and the evidence base is much smaller than for treatment-resistant depression. Spravato (esketamine) is not approved for any PTSD indication in Canada or the United States. The most rigorously studied psychedelic-assisted therapy for PTSD is MDMA-assisted therapy (MDMA-AT), which the FDA declined to approve in August 2024 and which remains accessible in Canada only through Health Canada's Special Access Program (SAP). This article walks through the actual ketamine evidence honestly, explains how veterans and first responders can navigate VAC and provincial workers' compensation coverage, and frames the MDMA-AT comparison without overstating either option.

Key takeaways

Ketamine for PTSD is off-label — Health Canada has approved ketamine as an anaesthetic only. Spravato is not approved for any PTSD indication.

The strongest PTSD-specific data comes from Feder et al. (2014 single-dose RCT, JAMA Psychiatry) and Feder et al. (2021 repeated-dose RCT, Am J Psychiatry) — both at Mount Sinai. Pooled meta-analyses since then (Du 2022, Sicignano 2024, Bryant 2023) show modest effect sizes that shrink against active controls.

For comorbid PTSD + treatment-resistant depression (TRD), repeated-dose ketamine has a stronger evidence base (Albott 2018) — and is where most ATMA CENA referrals fall.

VAC covers ketamine drug forms (IV, oral, intranasal, compounded cream) for service-related TRD and chronic pain on a case-by-case basis. VAC does not cover ketamine-assisted psychotherapy specifically.

The Workplace Safety and Insurance Board of Ontario (WSIB) lists ketamine and esketamine on the Psychotraumatic and Serious Injury formularies; presumptive PTSD legislation in Ontario and Alberta accelerates eligibility for first responders.

MDMA-assisted therapy has larger PTSD-specific RCT effect sizes (MAPP1, MAPP2 — Mitchell et al., Nature Medicine 2021/2023) but is FDA-rejected and Canada-SAP-only.

What is ketamine-assisted therapy for PTSD?

Ketamine therapy uses sub-anaesthetic doses of ketamine — a Health Canada-approved anaesthetic — paired with structured psychotherapy before, during, and after dosing. Health Canada has approved ketamine as an anaesthetic; psychiatric use is off-label, a legal and common practice in Canadian medicine. Spravato (intranasal esketamine) is Health Canada-approved for treatment-resistant MDD as of May 2020 — not for PTSD. All ketamine-for-PTSD in Canada uses racemic ketamine off-label.

For the full mechanism breakdown, see What Is Ketamine Therapy?.

How ketamine could affect PTSD circuits

The mechanistic story for ketamine in trauma rests on three layers (Aleksandrova et al., 2017; Lullau et al., 2023):

NMDA antagonism + glutamate surge. Ketamine blocks NMDA receptors on cortical GABAergic interneurons, producing a downstream surge of glutamate that activates AMPA receptors and triggers BDNF release.
Synaptogenesis in PFC and amygdala circuits. mTOR-pathway signalling drives the formation of new dendritic spines in prefrontal cortex (PFC), hippocampus, and amygdala within 24 to 72 hours of a dose.
Restored top-down inhibition of the amygdala. PTSD is characterized by amygdala hyperactivity to trauma cues and weakened top-down regulation by ventromedial PFC. Ketamine's synaptogenic effect appears to strengthen this circuit, potentially reducing fear-cue reactivity and trauma-memory salience.

A separate, more speculative line of work suggests ketamine can open a memory reconsolidation window during which a re-activated trauma memory is briefly malleable — and during which exposure-based psychotherapy may be more effective. This is the rationale behind Pradhan's TIMBER protocol and combined ketamine + prolonged exposure trials.

What the PTSD-specific evidence actually shows

The peer-reviewed PTSD-specific data on ketamine is real but modest. Here's what's been published.

Single-dose RCT — Feder 2014

Feder et al. 2014 — JAMA Psychiatry — was the first randomized active-controlled trial of ketamine in chronic PTSD. Forty-one patients (mean illness duration ~14.6 years) received single-dose IV ketamine 0.5 mg/kg or active control midazolam in a crossover design. The primary outcome (Impact of Event Scale–Revised at 24 hours) showed a 12.7-point greater reduction with ketamine (95% CI 2.5–22.8; p=0.02). Acute response was large; durability extended to roughly 2 weeks in responders (PubMed).

Repeated-dose RCT — Feder 2021

Feder et al. 2021 — American Journal of Psychiatry — extended the work to repeated dosing. Thirty patients with chronic PTSD received six infusions of 0.5 mg/kg ketamine or 0.045 mg/kg midazolam over two weeks (Monday–Wednesday–Friday). The primary outcome — change in CAPS-5 from baseline to week 2 — was 11.88 points greater in the ketamine arm (Cohen's d = 1.13; 95% CI 0.36–1.91). Onset was within 24 hours of the first infusion; median time to relapse in responders was approximately 27.5 days (PubMed).

Comorbid PTSD + TRD — Albott 2018

Albott et al. 2018 — Journal of Clinical Psychiatry — was an open-label trial of six ketamine infusions in 15 patients with comorbid PTSD and treatment-resistant depression. PTSD remission was achieved by 80% (12 of 15); TRD response by 93% (14 of 15). Median time to PTSD relapse was ~41 days; for depression, ~20 days. This is the most directly relevant evidence for the most common ATMA CENA referral profile: comorbid PTSD + TRD.

TIMBER + ketamine — Pradhan 2017

Pradhan et al. 2017 — TIMBER psychotherapy + low-dose ketamine — was a small (N=10) pilot RCT. The combined arm showed prolonged response duration versus TIMBER + placebo (median ~33 vs ~25 days, non-significant given small N). The clinical lesson — that timing of psychotherapy matters around ketamine dosing — informs the KAP integration framework ATMA CENA uses.

Pooled meta-analyses — the honest signal

Three recent meta-analyses provide the most realistic effect-size estimates:

Du et al. 2022 — Frontiers in Psychiatry — systematic review of 6 RCTs through May 2021. Single or repeated IV ketamine produces rapid PTSD symptom reductions; effects modest with high heterogeneity (PMC).
Sicignano et al. 2024 — Annals of Pharmacotherapy — 6-RCT meta-analysis. Pooled CAPS reduction MD = -10.63 points (95% CI -14.95 to -6.32); PCL reduction MD = -6.13 (95% CI -8.61 to -3.64); MADRS reduction MD = -6.33 (95% CI -8.97 to -3.69). Statistically significant but modest (PubMed).
Bryant et al. 2024 — European Journal of Psychotraumatology — pooled 52 effect sizes from 6 RCTs (N=221). Omnibus Hedges' g = 0.27 (95% CI 0.03–0.51); after trim-and-fill bias correction, g = 0.20 (95% CI -0.08 to 0.48). Against active midazolam controls specifically, the 24-hour effect was g = 0.24 (95% CI -0.30 to 0.78) — not statistically distinguishable from active control (PMC).

The honest summary: ketamine reduces PTSD symptoms rapidly, the effect is real, and it is meaningfully smaller than either ketamine's effect in TRD or MDMA-assisted therapy's effect in PTSD. Most of ketamine's PTSD signal in patients who present comorbid TRD + PTSD likely runs through the depression effect.

How MDMA-assisted therapy compares — honest framing

MDMA-AT is the leading psychedelic-assisted therapy specifically studied for PTSD. The MAPP1 (Mitchell et al., Nature Medicine 2021; PubMed) and MAPP2 (Mitchell et al., Nature Medicine 2023; PubMed) Phase 3 trials reported between-group effect sizes around d = 0.91–1.0 for CAPS-5 reduction — substantially larger than ketamine's PTSD effects in pooled analyses.

Two Canadian-relevant facts:

The FDA declined to approve MDMA-AT in August 2024 following its complete-response letter citing trial-design and safety-data concerns. Lykos Therapeutics is reportedly pursuing additional studies.
In Canada, MDMA for PTSD is accessible only via Health Canada's Special Access Program (SAP). SAP authorizations are case-specific, prescriber-initiated, and capacity-limited. As of recent reporting, MDMA SAP approvals in Canada have been substantially fewer than psilocybin (a few dozen versus several hundred). The 2025 SAP approval rate for psychedelic-assisted therapy reportedly declined further.

The honest takeaway: MDMA-AT has stronger PTSD-specific RCT evidence; ketamine is more accessible in Canada because it is off-label legal rather than SAP-gated. Patients who want the strongest evidence base for PTSD-specific psychedelic-assisted therapy should ask their prescriber about the SAP pathway for MDMA. Patients who need an accessible Canadian option now, particularly with comorbid TRD, may find ketamine the realistic next step.

This article does not promote MDMA. It acknowledges the comparison because patients deserve honest framing.

Coverage for Canadian veterans and first responders

PTSD coverage is one of the most navigable insurance pathways in Canadian mental health.

Veterans Affairs Canada (VAC)

VAC covers ketamine in IV, oral, intranasal, and compounded cream forms for service-related treatment-resistant depression and chronic pain on a case-by-case basis. VAC does not cover ketamine-assisted psychotherapy (the psychotherapy wraparound) at the time of last review, citing insufficient evidence. The drug itself is covered with prescriber justification.

For PTSD specifically — VAC does not list ketamine as a PTSD-indicated drug. The realistic VAC pathway for many veterans is treatment-resistant depression secondary to service-related PTSD, which is medically and administratively legitimate where the comorbidity is present and documented.

For Canadian veterans served by the provider's Edmonton or Calgary corporate clinics, intake screens for VAC eligibility on the depression pathway during the information call. See Insurance Coverage for Ketamine Therapy for the full pathway.

WSIB Ontario — Psychotraumatic formulary

WSIB Ontario lists ketamine and esketamine on the Psychotraumatic (22WS) and Serious Injury (27WS) formularies, alongside Musculoskeletal, CNS/PNS, and Chronic Pain formularies — see the WSIB ketamine and esketamine formulary decision. Coverage requires prior authorization. Ontario's presumptive PTSD legislation for first responders (firefighters, police, paramedics, dispatchers, corrections officers, and — as of October 2024 — wildland firefighters and wildland fire investigators) accelerates eligibility for the underlying PTSD diagnosis but does not auto-approve off-label ketamine; clinical justification is still required.

WCB Alberta — presumptive PTSD coverage

Alberta extends presumptive PTSD coverage to first responders under Bill 27. WCB Alberta covers ketamine on a case-by-case basis where traditional therapies have failed; see WCB Alberta procedures: pharmaceutical ketamine and esketamine.

Other workers' compensation boards

WorkSafeBC, WCB Manitoba, WCB Saskatchewan, WCB Nova Scotia, and CNESST Quebec review ketamine claims case-by-case without formal listings equivalent to WSIB Ontario or WCB Alberta.

Who is a candidate?

Most Canadian ketamine programs use the following inclusion criteria for PTSD-related referrals:

Adults 18 or older
DSM-5 diagnosis of PTSD with documented adequate trials of first-line treatments (trauma-focused CBT, prolonged exposure therapy, EMDR; SSRIs/SNRIs at therapeutic dose for ≥6 weeks)
Medically stable; able to provide informed consent
Realistic expectations grounded in the evidence base described above

Absolute contraindications: active psychosis, uncontrolled severe hypertension, severe cardiovascular disease, current pregnancy, anaphylactic reaction to ketamine, active manic episode.

Relative contraindications and considerations: active substance use disorder, severe dissociative symptoms (some PTSD patients with prominent depersonalization/derealization may find ketamine's dissociation re-traumatizing — this is a meaningful screening conversation), recent stroke, untreated severe sleep apnea, concurrent MAOIs or high-dose benzodiazepines (benzodiazepines may blunt ketamine's effect, and many PTSD patients are on chronic benzodiazepines).

For full eligibility detail, see How to Qualify for Ketamine Therapy in Canada.

What does ketamine therapy cost?

ATMA CENA's published KAT pricing applies across the network: KAT Psychedelic Pathway from CAD $1,585 + $795 per additional session; KAT Psycholytic Pathway from CAD $1,530 + $740 per additional session; customized programs CAD $2,325–$6,930. A non-refundable deposit of CAD $300 applies. For the full Canadian pricing context, see Ketamine Therapy Cost in Canada.

For VAC-eligible veterans, WSIB-eligible Ontario first responders, and WCB-eligible Alberta first responders, the drug cost component may be fully or partly covered with prior authorization. The psychotherapy wraparound is typically out-of-pocket or covered through extended-health benefits.

Frequently asked questions

Is ketamine approved for PTSD in Canada? No. Ketamine is approved by Health Canada as an anaesthetic. Any psychiatric use, including for PTSD, is off-label. Spravato (esketamine) is approved only for treatment-resistant depression — not for PTSD.

What's the strongest evidence for ketamine in PTSD? The Feder et al. 2014 single-dose RCT (JAMA Psychiatry) and Feder et al. 2021 repeated-dose RCT (Am J Psychiatry) are the landmark studies. Three recent meta-analyses (Du 2022, Sicignano 2024, Bryant 2023) show modest pooled effects that shrink against active controls. The Albott 2018 open-label trial in comorbid PTSD + TRD is the most directly relevant evidence for the most common referral profile.

Should I be considering MDMA-assisted therapy instead? MDMA-AT has stronger PTSD-specific RCT evidence (MAPP1, MAPP2) but is FDA-rejected and accessible in Canada only through Health Canada's Special Access Program. MDMA-AT availability is capacity-limited; ketamine is accessible now off-label. The right answer depends on your access pathway, urgency, and prescriber. ATMA CENA can discuss both honestly during the information call.

Does VAC cover ketamine for veterans with PTSD? VAC covers ketamine drug forms (IV, oral, intranasal, compounded cream) for service-related treatment-resistant depression and chronic pain on a case-by-case basis. VAC does not list ketamine as a PTSD-specific indication. The realistic VAC pathway for many veterans is documented TRD comorbid with service-related PTSD. VAC does not cover ketamine-assisted psychotherapy specifically.

Does WSIB cover ketamine for first responders with presumptive PTSD? WSIB Ontario lists ketamine and esketamine on the Psychotraumatic and Serious Injury formularies with prior authorization. Presumptive PTSD legislation accelerates eligibility for the underlying diagnosis but does not auto-approve off-label ketamine; clinical justification is required.

How fast does ketamine work for PTSD, and how long does it last? The Feder trials showed reductions within 24 hours of a single dose, sustained ~2 weeks in single-dose responders. Repeated dosing (six infusions over 2 weeks) extended response with median time-to-relapse ~27.5 days. For sustained relief, repeated/maintenance dosing combined with trauma-focused psychotherapy is the realistic protocol.

Can ketamine be combined with prolonged exposure therapy or EMDR? Yes, and the mechanistic rationale (reconsolidation window, enhanced extinction learning) is plausible. Pradhan's TIMBER protocol formalized one combination. In practice, KAP integration sessions with a trauma-trained therapist are standard around dosing — formal combined ketamine + prolonged exposure protocols are research-stage.

What if my PTSD is part of treatment-resistant depression? This is the most common ATMA CENA referral profile. Albott 2018 found that six ketamine infusions in patients with comorbid PTSD + TRD produced PTSD remission in 80% and depression response in 93%. The evidence in this comorbid profile is stronger than for PTSD alone, and VAC/WSIB pathways generally apply on the TRD side.

Will I dissociate during the session? What if dissociation is part of my PTSD? Sub-anaesthetic ketamine produces transient dissociation lasting roughly 30–60 minutes after dosing. For PTSD patients with prominent depersonalization/derealization, this is a meaningful screening conversation. Some patients find the experience valuable; others find it re-traumatizing. Honest preparation, a trauma-trained therapist, and a low first dose are standard mitigations. The ATMA CENA intake call includes this explicitly.

Are benzodiazepines a problem? Many PTSD patients are on chronic benzodiazepines. Benzodiazepines may blunt ketamine's antidepressant and anxiolytic effect. ATMA CENA's clinical team will discuss whether dose timing or tapering is appropriate for your situation; this is rarely a hard exclusion but is a meaningful pharmacodynamic consideration.

Where can I get ketamine therapy for PTSD in Canada? See the city- and province-specific articles in this cluster: Calgary, Edmonton, Winnipeg, Toronto/GTA, Vancouver, Halifax, Ottawa, Montreal, Saskatoon, Mississauga, Hamilton, London ON, Victoria BC, Kelowna.

Sources

ATMA CENA — Psychedelic-Assisted Therapy (pricing): https://psychedelic.healthcare/
Feder A, et al. (2014). Efficacy of intravenous ketamine for treatment of chronic PTSD: a randomized clinical trial. JAMA Psychiatry. https://pubmed.ncbi.nlm.nih.gov/24740528/
Feder A, et al. (2021). A randomized controlled trial of repeated ketamine administration for chronic PTSD. Am J Psychiatry. https://pubmed.ncbi.nlm.nih.gov/37404970/
Albott CS, et al. (2018). Efficacy, safety, and durability of repeated ketamine infusions for comorbid PTSD and TRD. J Clin Psychiatry. https://www.psychiatrist.com/jcp/repeated-ketamine-infusions-for-comorbid-ptsd-and-trd/
Pradhan B, et al. (2017). TIMBER psychotherapy + ketamine pilot RCT. https://www.researchgate.net/publication/318677183_Trauma_Interventions_using_Mindfulness_Based_Extinction_and_Reconsolidation_TIMBER_psychotherapy_prolong_the_therapeutic_effects_of_single_ketamine_infusion_on_post-traumatic_stress_disorder_and_co-mo
Du R, et al. (2022). Multivariate effect of ketamine on PTSD: systematic review and meta-analysis. Front Psychiatry. https://pmc.ncbi.nlm.nih.gov/articles/PMC8959757/
Sicignano DJ, et al. (2024). Impact of ketamine on PTSD: systematic review with meta-analyses. Ann Pharmacother. https://pubmed.ncbi.nlm.nih.gov/37776285/
Bryant J, et al. (2024). So how special is special K? Meta-analysis of ketamine for PTSD RCTs. Eur J Psychotraumatol. https://pmc.ncbi.nlm.nih.gov/articles/PMC10791091/
Ragnhildstveit A, et al. (2023). The potential of ketamine for PTSD: review of clinical evidence. Ther Adv Psychopharmacol. https://pmc.ncbi.nlm.nih.gov/articles/PMC9989422/
Mitchell JM, et al. (2021). MDMA-assisted therapy for severe PTSD: MAPP1 Phase 3. Nat Med. https://pubmed.ncbi.nlm.nih.gov/33972795/
Mitchell JM, et al. (2023). MDMA-assisted therapy for moderate to severe PTSD: MAPP2 Phase 3. Nat Med. https://pubmed.ncbi.nlm.nih.gov/37709999/
Aleksandrova LR, et al. (2017). Antidepressant mechanisms of ketamine — AMPA, mTOR, BDNF. Can J Psychiatry. https://pubmed.ncbi.nlm.nih.gov/28234212/
Lullau APM, et al. (2023). Antidepressant mechanisms of ketamine. Front Neurosci. https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2023.1223145/full
Veterans Affairs Canada — Mental Health Benefits: https://www.veterans.gc.ca/en/financial-programs-and-services/medical-costs/coverage-services-prescriptions-and-devices/mental-health-benefits
WSIB Ontario — Ketamine and Esketamine Formulary Decision: https://www.wsib.ca/en/drug-formulary-listing-decision-ketamine-and-esketamine

Ketamine Therapy for PTSD

Ketamine and esketamine access