Ketamine Maintenance Therapy: How to Sustain Your Results Long-Term

By Kyle Roth, FNP-BC, APRN, MSN, MHA | Roth Family Medicine and Mental Health | Pocatello, Idaho

The initial ketamine series — typically 6 infusions over 2–3 weeks — produces rapid, often dramatic antidepressant effects in patients with treatment-resistant depression. For many patients, this represents the first meaningful relief they've experienced in years.

But a common and important question follows: How long will it last? And what do I need to do to sustain it?

The honest answer is that ketamine's effects are not permanent without ongoing attention. The duration of benefit varies significantly between patients, and sustaining long-term results requires a thoughtful approach to maintenance therapy, integration, and lifestyle. This article explains what the evidence shows and what a comprehensive long-term ketamine treatment plan looks like.

The duration of antidepressant benefit after an initial ketamine series varies considerably:

• Responders: Approximately 50–70% of patients with TRD show significant improvement after the initial series
• Duration of benefit: Studies report a median duration of 2–3 weeks after a single infusion; after a 6-infusion series, many patients maintain benefit for 4–8 weeks, with some maintaining benefit for 3–6 months or longer
• Individual variation: Some patients maintain benefit for months after the initial series; others notice return of symptoms within weeks
• Predictors of longer duration: Younger age, shorter duration of depression, lower baseline severity, engagement with therapy and lifestyle optimization, and absence of ongoing major stressors

The variability in duration is one of the most important clinical realities of ketamine therapy — and it's why maintenance planning is essential from the beginning.

Ketamine's antidepressant mechanism involves rapid promotion of neuroplasticity — the brain's ability to form new synaptic connections and reorganize neural circuits. This neuroplasticity is not just a mechanism of the acute antidepressant effect; it creates a window of enhanced plasticity in the days and weeks following infusions.

During this window:

• The brain is more receptive to new learning and behavioral change
• Psychotherapy is more effective — insights are more accessible and behavioral changes more achievable
• Lifestyle changes (exercise, sleep, diet) have greater neurobiological impact
• Negative patterns and rumination are more amenable to interruption

This is why the period immediately following ketamine infusions is not just a time to feel better — it's a time to actively build the psychological and behavioral foundations that will sustain the improvement.

Key Reference: Duman RS, et al. (2016). Synaptic plasticity and depression: new insights from stress and rapid-acting antidepressants. Nature Medicine, 22(3), 238–249.

There is no single universally established maintenance protocol for ketamine therapy — this is an area of active clinical research. Current approaches are based on clinical experience, emerging evidence, and individualized patient response.

The most common approach is scheduled maintenance infusions at intervals determined by the patient's response pattern:

Monthly maintenance: The most commonly used interval. After the initial 6-session series, patients receive one infusion per month. This approach is appropriate for patients who maintain good benefit between sessions.

Every 2–3 weeks: For patients who notice symptom return within 2–3 weeks of their last infusion, more frequent maintenance may be needed initially, with gradual spacing as stability improves.

As-needed (PRN) maintenance: Some patients achieve prolonged remission after the initial series and use maintenance infusions only when symptoms begin to return. This approach requires good self-monitoring and a low threshold for scheduling a maintenance session.

Booster series: Some patients benefit from periodic "booster series" of 2–3 infusions when symptoms return, rather than single maintenance infusions.

FDA-approved intranasal esketamine (Spravato) has an established maintenance protocol: twice weekly for 4 weeks (acute phase), then weekly for 4 weeks, then every 1–2 weeks (maintenance phase). This protocol is supported by clinical trial data and is covered by many insurance plans.

For patients who respond to IV ketamine, transitioning to Spravato for maintenance can provide a more convenient and potentially more affordable long-term option.

Maintenance infusions alone are not sufficient for optimal long-term outcomes. The neuroplasticity that ketamine promotes must be directed toward building lasting change — through what is called integration.

The most important integration practice is engaging with psychotherapy during and after the ketamine treatment course. The neuroplasticity window created by ketamine makes psychotherapy more effective — insights are more accessible, behavioral changes more achievable, and entrenched patterns more amenable to change.

Recommended approaches:

• Cognitive Behavioral Therapy (CBT): Addresses the cognitive distortions and behavioral patterns that maintain depression
• Acceptance and Commitment Therapy (ACT): Builds psychological flexibility and values-based action
• EMDR: Particularly relevant for patients with trauma contributing to depression
• Psychodynamic therapy: For patients whose depression has deep relational or developmental roots

Many patients find that journaling in the days following infusions — capturing insights, emotional experiences, and intentions — helps consolidate the psychological work of the session and maintain the gains.

The lifestyle factors that support neuroplasticity and antidepressant response are particularly important during the maintenance phase:

Exercise: Regular aerobic exercise promotes BDNF and neuroplasticity, extending and deepening ketamine's effects. We recommend establishing a consistent exercise routine during the initial ketamine series and maintaining it through the maintenance phase.

Sleep: Adequate, quality sleep is essential for neuroplasticity consolidation. Sleep is when the brain processes and consolidates the changes initiated by ketamine.

Diet: Anti-inflammatory dietary patterns (Mediterranean diet) support the neurobiological environment that ketamine's effects depend on.

Stress management: Chronic stress activates the HPA axis and drives neuroinflammation, counteracting ketamine's neuroplasticity-promoting effects. Mindfulness, social connection, and stress reduction practices are important maintenance supports.

Effective maintenance requires ongoing monitoring and willingness to adjust:

Symptom tracking: We recommend that patients track their mood, energy, and functioning using validated scales (PHQ-9) between sessions. This provides objective data to guide maintenance scheduling.

Early intervention: The best time to schedule a maintenance infusion is when symptoms begin to return — not after a full relapse. Patients who learn to recognize their early warning signs and schedule proactively have better long-term outcomes.

Medication optimization: Ketamine maintenance is most effective when combined with optimized antidepressant medication. We regularly review and adjust medications to support the ketamine response.

Addressing contributors: Ongoing attention to inflammatory markers, hormonal status, vitamin D, sleep quality, and other functional medicine factors that influence antidepressant response.

For patients who achieve good response to ketamine but find the maintenance burden (cost, time, frequency) challenging, TMS is an excellent option for long-term maintenance. TMS works through a different mechanism and can sustain the gains achieved with ketamine while providing a more structured, insurance-covered maintenance option.

The combination of ketamine (for rapid initial response) followed by TMS (for sustained maintenance) is an increasingly used clinical approach.

How will I know when I need a maintenance infusion? Most patients develop a sense of their own early warning signs — subtle changes in sleep, energy, motivation, or mood that precede a full return of depression. We encourage patients to track these signs and schedule proactively rather than waiting for full relapse.

Can I reduce maintenance frequency over time? Yes — many patients find that as they build psychological resilience through therapy and lifestyle optimization, they can gradually space maintenance infusions further apart. The goal is to use the neuroplasticity window to build lasting change that reduces dependence on ongoing infusions.

What if ketamine stops working over time? Tachyphylaxis to ketamine is less common than with SSRIs but can occur. If response diminishes, we reassess the full treatment picture — medication optimization, inflammatory status, hormonal status, and lifestyle factors — and consider alternative or adjunctive approaches including TMS.

1. Duman RS, et al. Synaptic plasticity and depression: new insights from stress and rapid-acting antidepressants. Nat Med. 2016;22(3):238–249.
2. Murrough JW, et al. Rapid and longer-term antidepressant effects of repeated ketamine infusions in treatment-resistant major depression. Biol Psychiatry. 2013;74(4):250–256.
3. Daly EJ, et al. Efficacy and safety of intranasal esketamine adjunctive to oral antidepressant therapy in treatment-resistant depression. JAMA Psychiatry. 2018;75(2):139–148.

Medical Disclaimer: This content is for educational purposes only and does not constitute medical advice.

Kyle Roth, FNP-BC, APRN, MSN, MHA | Roth Family Medicine and Mental Health | Pocatello, Idaho | 208-904-4705 | www.rothfamilymed.com