Treatment-Resistant PTSD

The short version

●PTSD is treatment-resistant when symptoms persist despite an adequate course of trauma-focused therapy (such as prolonged exposure, CPT, or EMDR) and/or an adequate medication trial.
●Trauma-focused psychotherapy is the most effective treatment and should be central; SSRIs (sertraline, paroxetine) are the FDA-approved medications but help a minority fully.
●A randomized controlled trial found a single ketamine infusion produced rapid reduction in core PTSD symptoms.¹
●A later randomized trial of repeated ketamine infusions showed efficacy in chronic PTSD over two weeks — the strongest evidence to date.²
●Ketamine doesn't erase memories; it appears to reduce symptom severity and may open a window in which trauma-focused therapy is easier to engage.
●Tovani treats PTSD; ketamine is best paired with trauma-focused therapy rather than used alone.³

Clinical definition

Post-traumatic stress disorder develops after exposure to actual or threatened death, serious injury, or sexual violence, and is defined by four symptom clusters: intrusion (flashbacks, nightmares), avoidance, negative alterations in cognition and mood, and marked alterations in arousal and reactivity (hypervigilance, startle, sleep disturbance), persisting more than a month. PTSD is considered treatment-resistant when these symptoms remain clinically significant despite an adequate trial of evidence-based trauma-focused psychotherapy and/or pharmacotherapy. Because trauma-focused therapy is both the most effective treatment and the hardest to tolerate, apparent resistance sometimes reflects an inability to engage with exposure-based work rather than true non-response.

How it differs from related conditions

vs. PTSD

Treatment-resistant PTSD is the same disorder after first-line treatments have failed; the distinction is the treatment history.

vs. Complex PTSD

C-PTSD adds pervasive difficulties with emotion regulation, self-concept, and relationships from prolonged or repeated trauma — often needing longer, phased treatment.

vs. Major depressive disorder

Depression very commonly co-occurs with PTSD; treating one without the other limits recovery, and ketamine may help a co-occurring depression as well.

First-line treatments

Trauma-focused psychotherapy

Prolonged exposure, cognitive processing therapy (CPT), and EMDR have the strongest evidence and are the foundation of PTSD care.

SSRIs (sertraline, paroxetine)

The FDA-approved medications for PTSD; helpful for some, but full response is the exception rather than the rule.

Prazosin for nightmares

Targets trauma-related nightmares and sleep disruption in selected patients.

Avoiding benzodiazepines

Benzodiazepines are discouraged in PTSD — they don't treat core symptoms and may worsen outcomes.

When standard treatments fail

When PTSD persists despite trauma-focused therapy and medication, options include switching or intensifying the psychotherapy, augmentation strategies, and rapid-acting treatments. Repeated intravenous ketamine has randomized-trial support in chronic PTSD, and current Cochrane evidence continues to weigh the modest role of pharmacotherapy overall. The most durable gains usually come from combining symptom reduction with renewed engagement in trauma-focused work.

Where ketamine fits

Ketamine has the strongest randomized evidence of any glutamatergic agent in PTSD. A proof-of-concept RCT showed a single infusion rapidly reduced core PTSD symptoms,¹ and a subsequent randomized trial of repeated infusions over two weeks demonstrated efficacy in chronic PTSD — the most rigorous evidence available.² Mechanistically, ketamine doesn't remove memories; by reducing symptom severity and promoting neuroplasticity, it may create a window in which avoidance is lower and trauma-focused therapy becomes more accessible. That is why it is best used as a catalyst alongside therapy rather than as a standalone treatment, a framing consistent with broader PTSD pharmacotherapy evidence.³

Where this fits with Tovani

Tovani treats PTSD, and the most effective use of ketamine here is in combination with trauma-focused therapy — ketamine to reduce symptom intensity and open a window of plasticity, therapy to process the trauma and consolidate gains. We encourage patients to be engaged in (or starting) trauma-focused work, and we screen for the stability needed for at-home treatment. Ketamine is a catalyst, not a replacement for processing the trauma.

Check eligibility Find treatment options The science behind ketamine

Frequently asked

Does ketamine work for PTSD?

It has the strongest randomized evidence of any glutamate-based treatment for PTSD. One trial showed a single infusion rapidly reduced symptoms, and a later trial of repeated infusions showed efficacy in chronic PTSD. It works best combined with trauma-focused therapy, not on its own.

Will ketamine erase my traumatic memories?

No — it doesn't remove memories. It appears to reduce symptom severity and promote neuroplasticity, which may make avoidance lower and trauma-focused therapy easier to engage in. The therapy is what processes the trauma; ketamine helps open the door.

My PTSD hasn't improved with therapy — what now?

First, consider whether you've had a full course of trauma-focused therapy (prolonged exposure, CPT, or EMDR), which is the most effective treatment and the hardest to tolerate. If symptoms persist despite that and medication, repeated ketamine has randomized-trial support and may make renewed therapy more accessible.

Can I do ketamine instead of trauma therapy?

We don't recommend it as a replacement. The evidence and the mechanism both point to ketamine working best as a catalyst alongside trauma-focused therapy — reducing symptom intensity so the processing work becomes possible. Ketamine alone tends to be less durable.

References

Feder A et al. 2014, JAMA Psychiatry — Randomized controlled trial: a single IV ketamine infusion rapidly reduced symptoms of chronic PTSD. (PMID 24740528)
Feder A et al. 2021, American Journal of Psychiatry — Randomized controlled trial of repeated ketamine infusions showing efficacy in chronic PTSD. (PMID 33397139)
Williams T et al. 2025, Cochrane Database of Systematic Reviews — Systematic review of pharmacotherapy for PTSD, contextualizing medication's overall role. (PMID 42206608)

Last reviewed by Dr. Ben Soffer, DO on June 2, 2026. This page is educational and not a substitute for clinical evaluation. A physician determines whether ketamine therapy is appropriate for your specific situation.