6 Weeks of Oral Ketamine for TRD, PTSD, and OCD

Most ketamine research focuses on a single diagnosis — usually depression. But in clinical practice, patients rarely come in with just one condition. Treatment-resistant depression often coexists with PTSD, anxiety, or OCD. A 2025 open-label study led by Beaglehole and colleagues tested what happens when you treat patients across multiple diagnoses with six weeks of oral ketamine. The findings suggest ketamine's benefits extend well beyond depression alone.

Study Overview

Beaglehole et al. designed an open-label trial enrolling patients with three distinct treatment-resistant conditions: treatment-resistant depression (TRD), post-traumatic stress disorder (PTSD), and obsessive-compulsive disorder (OCD). Participants had failed to respond to conventional treatments for their respective conditions and were administered oral ketamine over a six-week protocol.

This was not a placebo-controlled trial — open-label means both patients and clinicians knew the treatment being given. While this design cannot account for placebo effects with the same rigor as a blinded RCT, it provides valuable real-world data on how patients with different diagnoses respond to a standardized ketamine protocol.

Symptom severity was measured using validated scales appropriate for each condition: depression rating scales for TRD patients, PTSD-specific measures for trauma patients, and OCD severity scales for those with obsessive-compulsive symptoms.

Results Across All Three Conditions

The central finding was that oral ketamine produced clinically meaningful improvements across all three diagnostic groups. This was not a case where one condition responded well and the others showed marginal effects — patients with TRD, PTSD, and OCD all demonstrated significant reductions in symptom severity over the six-week treatment period.

Importantly, these improvements were sustained. Patients did not simply experience a brief spike in improvement followed by a rapid return to baseline. The six-week protocol appeared to support lasting symptom reduction, consistent with the hypothesis that repeated ketamine dosing promotes cumulative neuroplastic changes rather than merely providing transient symptom relief.

Tolerability was also favorable. The oral route of administration was well-tolerated across the study population, with side effects consistent with what has been reported in other oral ketamine trials — mild and transient dissociation, some nausea, and no serious adverse events requiring treatment discontinuation.

Why Multi-Indication Findings Matter

The significance of this study lies in its multi-indication design. In the real world, psychiatric comorbidity is the norm, not the exception. Research estimates suggest that:

• Up to 50% of patients with major depression also meet criteria for an anxiety disorder
• PTSD frequently co-occurs with depression, substance use disorders, and OCD
• OCD patients often experience comorbid depression and anxiety

When a treatment works across multiple conditions, it suggests the mechanism of action targets something fundamental rather than something diagnosis-specific. Ketamine's effects on glutamate signaling, BDNF-mediated neuroplasticity, and neural circuit connectivity may represent a transdiagnostic therapeutic mechanism — one that addresses shared neurobiological disruptions across depression, trauma, and obsessive-compulsive disorders.

For patients carrying multiple diagnoses, this is particularly relevant. Rather than stacking three or four different medications to address each condition separately, ketamine may offer a single intervention that provides relief across the board.

Oral Ketamine as the Delivery Method

The choice of oral ketamine as the delivery method in this study is noteworthy. IV ketamine, while well-studied for depression, presents logistical barriers for patients who need ongoing treatment — especially those in rural areas or those managing the functional impairment that comes with severe psychiatric illness.

Oral ketamine can be administered at home under medical supervision, making it a more sustainable option for the kind of multi-week treatment protocol used in this study. This aligns with the model Isha Health uses for at-home ketamine therapy, where patients receive sublingual ketamine troches and work with their clinical team remotely.

Implications for Treatment-Resistant Patients

For patients who have not responded to standard treatments, this study adds to a growing body of evidence that oral ketamine deserves consideration — and not just for depression. The data supporting ketamine for treatment-resistant depression is the most robust, but the Beaglehole study extends that evidence to PTSD and OCD in a meaningful way.

The six-week duration also matters. It demonstrates that oral ketamine can be administered over a clinically relevant time frame with sustained benefit, which is important for treatment planning and patient expectations.

To see how ketamine therapy performs in real-world clinical practice, review Isha Health's outcomes data from over 500 patients. For those interested in starting treatment, learn more about our online ketamine therapy program.

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Related Articles

• Ketamine for Treatment-Resistant Depression
• Ketamine for PTSD
• Ketamine for OCD

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