Introduction
While much clinical attention focuses on initiating ketamine therapy -- patient selection, dosing protocols, and response assessment -- the question of when and how to discontinue treatment is equally important and often less well-defined. Ketamine therapy is not intended as an indefinite intervention for all patients, yet premature discontinuation risks relapse in a population that has, by definition, failed multiple prior treatments.
This guide provides a framework for clinicians managing the discontinuation process, including clinical criteria for considering cessation, tapering strategies, relapse monitoring protocols, and transition planning.
When to Consider Discontinuation
Sustained Remission
The strongest indication for considering discontinuation is sustained remission -- defined as depression rating scores (PHQ-9 <5, MADRS <10) maintained over a period of at least 3-6 months on a stable maintenance ketamine regimen. Brief fluctuations above the remission threshold do not reset this timeline, but a sustained return to moderate or severe depression scores warrants reassessment.
Key factors that support a discontinuation attempt:
- Remission maintained for 3+ months on a stable or decreasing ketamine frequency
- Concurrent antidepressant medication optimized and at therapeutic doses
- Active engagement in psychotherapy, particularly evidence-based modalities (CBT, DBT, EMDR) that provide durable skill acquisition
- Stable psychosocial circumstances (housing, employment, relationships)
- Patient motivation and understanding of the monitoring plan
Lack of Response
Patients who fail to achieve meaningful response (defined as <25% improvement on primary outcome measures) after an adequate trial -- typically 6-8 IV infusions or 8-12 sublingual sessions with dose optimization -- should be discontinued from the current protocol. This does not necessarily mean abandoning ketamine entirely; a route change, dose adjustment, or treatment pause followed by rechallenge may be considered.
Adverse Effects
Discontinuation is warranted when adverse effects outweigh therapeutic benefit:
- Persistent or worsening cognitive impairment between sessions
- Unmanageable cardiovascular responses despite dose adjustment
- Urological symptoms (frequency, urgency, dysuria) suggestive of bladder toxicity
- Escalating dosing demands suggestive of tolerance development
- Emergence of problematic use patterns (dose escalation without clinical supervision, obtaining ketamine from additional sources)
Patient Preference
Some patients who have achieved sustained improvement express a preference to discontinue ketamine and manage their condition with other modalities. This preference should be respected and supported with a structured discontinuation plan.
Tapering Protocols
General Principles
Ketamine discontinuation should follow a gradual frequency reduction rather than abrupt cessation. While ketamine does not produce the physiological dependence and withdrawal syndrome characteristic of benzodiazepines or opioids, several factors support gradual tapering:
- Depressive symptom rebound can occur within days to weeks of the last treatment, and gradual tapering allows detection of rebound before complete cessation
- Psychological dependence on the treatment experience may develop, and abrupt discontinuation can provoke anxiety about relapse
- A stepwise approach provides data about the patient's tolerance for extended treatment intervals, informing the pace of the taper
IV Infusion Tapering
For patients on maintenance IV infusions, a typical tapering protocol:
Phase 1 -- Interval extension: Increase the interval between infusions by 1-2 weeks at each step. For example, a patient on every-2-week infusions would move to every 3 weeks, then every 4 weeks, with symptom assessment at each visit.
Phase 2 -- Further extension: Continue extending intervals to every 5-6 weeks, then every 8 weeks. Monitor for symptom recurrence at each step.
Phase 3 -- Trial discontinuation: After 2-3 sessions at the longest tolerated interval (e.g., every 8 weeks) with maintained remission, schedule a trial discontinuation period with planned reassessment at 4-week intervals.
Timeline: The total tapering process typically spans 3-6 months from initiation of interval extension to trial discontinuation.
Sublingual/Oral Tapering
For patients on at-home sublingual or oral ketamine, tapering may involve frequency reduction, dose reduction, or both:
Frequency reduction: Decrease from three times weekly to twice weekly, then once weekly, then every other week. Maintain each frequency for at least 2-3 weeks before the next reduction.
Dose reduction: At each frequency step, the dose may be maintained or reduced. Some clinicians prefer to reduce frequency first (maintaining therapeutic dose per session), then reduce dose at the lowest frequency before discontinuation.
Combined approach: Alternate between frequency and dose reductions. For example, reduce from 200 mg three times weekly to 200 mg twice weekly, then to 150 mg twice weekly, then to 150 mg once weekly, then to 100 mg once weekly, then discontinue.
Relapse Monitoring
Assessment Schedule During Tapering
Systematic outcome measurement is critical during the tapering process. The recommended assessment schedule:
- PHQ-9 or QIDS-SR: At every treatment session during the taper and at planned check-in visits between sessions
- C-SSRS: At each visit for patients with a history of suicidal ideation
- Functional assessment: Brief inquiry into sleep, work functioning, social engagement, and daily routine at each visit
- Scheduled follow-ups after discontinuation: At 2 weeks, 4 weeks, 8 weeks, and 12 weeks post-discontinuation, then monthly for 6 months
Defining Relapse
Clinicians should establish clear, pre-defined criteria for relapse that trigger clinical action:
- PHQ-9 increase of 5 or more points above the lowest score achieved during treatment
- Return to moderate depression range (PHQ-9 10+) on two consecutive assessments
- Re-emergence of suicidal ideation (any C-SSRS positive screen)
- Patient-reported functional decline consistent with depressive relapse
- Clinical judgment that the patient's condition has meaningfully deteriorated
Response to Relapse
If relapse criteria are met during tapering:
- Pause the taper: Return to the last effective treatment frequency for 4-6 weeks to restabilize
- Reassess: Evaluate for precipitating factors (medication changes, psychosocial stressors, medical illness)
- Address modifiable factors: Optimize concurrent medications, increase psychotherapy frequency, address psychosocial stressors
- Reattempt taper: After restabilization, consider a slower taper schedule
If relapse occurs after complete discontinuation:
- Reinitiate ketamine: A brief reinduction course (3-4 sessions) rather than the full 6-session induction is often sufficient
- Reassess discontinuation timeline: The patient may require a longer maintenance period before the next discontinuation attempt
- Consider indefinite maintenance: Some patients require ongoing maintenance ketamine, and this should be discussed honestly rather than repeatedly attempting discontinuation
Transition Planning
Strengthening Concurrent Treatments
Before and during the ketamine taper, clinicians should ensure that the patient's broader treatment plan is optimized:
- Medication optimization: Review and optimize oral antidepressant regimen. The period of ketamine-induced remission provides an opportunity to titrate antidepressants to target doses and assess their independent efficacy
- Psychotherapy engagement: Encourage active engagement in evidence-based psychotherapy. Skills-based approaches (CBT, DBT) provide tools that persist after therapy ends, unlike medication effects that cease when medication is stopped
- Lifestyle interventions: Support exercise, sleep hygiene, social connection, and stress management practices that provide independent antidepressant benefit
Patient Education
Patients should understand:
- That discontinuation is a structured, monitored process with built-in safety nets
- The specific relapse signs to self-monitor between appointments
- That returning to ketamine treatment is an acceptable and expected option if relapse occurs -- it does not represent failure
- The importance of maintaining other treatment components (medication, therapy, lifestyle) during and after the ketamine taper
- How to contact the treatment team urgently if significant symptom recurrence or suicidal ideation develops between scheduled visits
Communication with Other Providers
Notify all involved providers -- psychiatrist, therapist, primary care physician -- of the discontinuation plan. Establish a communication protocol for relapse detection, as other providers may observe changes before the ketamine clinician's next scheduled contact.
Special Considerations
Patients on Long-Term Maintenance
Patients who have been on maintenance ketamine for more than 12 months may require longer tapering timelines. These patients have adapted their coping and functioning to the treatment structure, and discontinuation involves not only pharmacological adjustment but also a shift in self-management patterns.
Seasonal Considerations
For patients with a seasonal component to their depression, timing the discontinuation to begin during their historically lower-risk season (typically late spring/summer) may improve success.
Pregnancy Planning
Female patients planning pregnancy should discuss ketamine discontinuation well in advance, as ketamine is not recommended during pregnancy. A structured taper completed before conception, with reinforced alternative treatments, is the preferred approach.
Conclusion
Discontinuing ketamine therapy is a clinical process that requires the same level of planning, monitoring, and individualization as the initiation phase. Gradual frequency reduction with systematic outcome assessment at each step enables safe tapering while providing early detection of relapse. Pre-defined relapse criteria, a structured monitoring schedule, and clear communication with patients and co-treating providers form the essential framework. Not all patients will successfully discontinue ketamine, and indefinite maintenance remains a valid clinical outcome when the alternative is relapse into treatment-resistant illness.
References
- Phillips JL, et al. Single and Repeated Ketamine Infusions for Reduction of Suicidal Ideation in Treatment-Resistant Depression. Neuropsychopharmacology. 2020;45(4):606-612 — Duration of ketamine effects and relapse patterns
- Sanacora G, et al. A Consensus Statement on the Use of Ketamine in the Treatment of Mood Disorders. JAMA Psychiatry. 2017;74(4):399-405 — Expert consensus including maintenance and discontinuation considerations
- Daly EJ, et al. Efficacy of Esketamine Nasal Spray Plus Oral Antidepressant Treatment for Relapse Prevention in Patients With Treatment-Resistant Depression. JAMA Psychiatry. 2019;76(9):893-903 — Relapse prevention data informing maintenance and discontinuation decisions
- Kryst J, et al. Efficacy of Single and Repeated Administration of Ketamine in Unipolar and Bipolar Depression. Pharmacol Rep. 2020;72(3):543-562 — Review of ketamine treatment duration and relapse
- National Institute of Mental Health: Treatment-Resistant Depression — NIMH overview of treatment approaches including long-term management
- Mayo Clinic: Depression Treatment — Clinical treatment decision-making framework
Share