People often ask the same question in different ways: How long does this take, and will I feel better after one session?
Ketamine treatment rarely works like a single appointment that “finishes” the problem. Most medical models treat it as a structured process that starts more intensively, then changes based on how your symptoms respond and how stable that improvement feels in real life.
If you understand the phases upfront, you can plan your time, track progress more clearly, and avoid the disappointment that comes from expecting a straight-line timeline.
Start With the Right Expectation: Ketamine Usually Works in Phases
Most providers build duration around phases because symptoms shift over time, and the safest schedule changes as your body adapts. Ketamine treatment for depression often begins with a front-loaded period, then moves toward less frequent sessions if you respond.
A clear example comes from the FDA-labeled schedule for intranasal esketamine (Spravato) in treatment-resistant depression. It follows a simple rhythm:
- Weeks 1–4: Dosing twice per week
- Weeks 5–8: Dosing once per week
- Week 9 and after: Dosing every 2 weeks or once weekly, depending on what maintains response
That last part points clinicians toward the least frequent schedule that still keeps symptoms under control, which means the plan can stretch or tighten depending on what you see in follow-up.
The Early Phase: Why the First 4–6 Weeks Matter Most
The early weeks carry a lot of weight because they give you the first real signal about direction. Ketamine depression therapy uses this window to answer a practical question: Are symptoms actually moving, or are you only feeling short-lived shifts that fade quickly?
Real-world IV ketamine outcomes from the U.S. Department of Veterans Affairs help ground this expectation. In a VA clinical practice sample of 215 patients, researchers tracked PHQ-9 depression scores and infusion patterns over time. The average starting PHQ-9 score measured 18.6, which sits in the moderately severe range. By about 6 weeks, 26% of patients met “response,” defined as at least a 50% improvement on the PHQ-9. About 15% reached remission, defined as PHQ-9 at or below 5.
The schedule also tells a story about duration. Patients moved from receiving infusions roughly every 5 days to receiving them every 3–4 weeks over the first 5 months. Over 12 months, the mean total reached 18 infusions. This pattern fits what patients often experience: frequent early visits, then wider spacing if the benefit holds.
How Providers Decide “How Long”
Once you understand the early phase, the next question becomes “How do you decide what comes next?” Psychiatric treatment decisions work best when they follow checkpoints instead of vibes, even when a patient feels impatient.
The FDA labeling for esketamine builds in clear reassessment moments. For the treatment-resistant depression schedule, clinicians reassess after the first four weeks of the twice-weekly phase, then adjust frequency based on response.
For adults with major depressive disorder and acute suicidal ideation or behavior, the label ties dosing to a more time-limited course: 84 mg twice weekly for 4 weeks, with a possible reduction to 56 mg for tolerability. The label also notes that treatment beyond four weeks for this specific indication has not been systematically evaluated, which pushes providers to reassess benefits and next steps rather than automatically continuing.
The VA data adds another kind of checkpoint. It shows that a meaningful subset of patients hit response or remission by about six weeks, and that benefits can persist as clinicians space visits out. The same study also flags uncertainty about “optimal infusion frequency,” which is a quiet way of saying that medicine still does not have a single perfect formula for everyone.
Why Visit Time and Monitoring Affect Duration More Than Patients Expect
Duration is not only about weeks on a calendar. Ketamine treatment also includes how long each appointment takes, because monitoring protects patients during the window when side effects peak.
For esketamine, the FDA requires observation in a healthcare setting for at least two hours after each session, with a clinical check to confirm stability before discharge. That requirement exists because sedation and dissociation show up often enough to plan around. In the prescribing information, 48% to 61% of patients developed sedation based on a standardized alertness scale. A smaller fraction, around 0.3% to 0.4%, experienced loss of consciousness. Dissociation or perceptual changes appeared in roughly 61% to 84% of patients in the trials summarized in the label.
Blood pressure shifts add another layer. The label reports mean maximum post-dose increases of about 7–10 mmHg systolic and 4–6 mmHg diastolic, depending on the group. Those numbers do not mean everyone runs into problems, but they explain why clinicians check vitals and why visit structure matters. Patients often feel surprised by the practical impact: You need transportation planning, you need time off work, and you need a schedule that supports safety rather than speed.
Ketamine Is Often One Part of a Longer Mental Health Plan
When people ask about duration, they often mean, “When can I stop thinking about this?” Ketamine for depression can help relieve symptoms, but most clinicians still anchor it inside a broader plan because depression rarely stays solved by one tool.
That broader plan usually focuses on stability. Providers look at your symptom pattern, your diagnosis, and what relapse risk looks like for you personally. They also track function, not only mood. If sleep stays unstable or anxiety stays high, the team may adjust timing, spacing, or the surrounding supports rather than simply adding more sessions.
In practice, the “right length” often looks like a phased course that supports improvement, followed by maintenance decisions that prioritize staying well over chasing a perfect endpoint.
The Goal Is Predictable Progress Rather Than a Perfect Timeline
Ketamine depression therapy usually starts with a structured early phase, then shifts based on what your symptoms do over the next several weeks. You can expect reassessment points, and you can expect your schedule to change if you improve.
Psychiatric treatment works best when you and your provider measure progress, name the risks, and adjust the plan with intention. That approach keeps duration from feeling random, and it helps you avoid the trap of comparing your timeline to someone else’s.
At Zeam, we treat ketamine care as a medically supervised process. If you want help understanding what a realistic timeline could look like for your symptoms, we can evaluate fit, walk through monitoring and safety, and build a plan that supports long-term stability. Contact us to schedule an assessment and discuss IV ketamine services, Spravato treatment, or ketamine-assisted psychotherapy.
Key Takeaways
- Ketamine treatment is typically delivered in phases, starting with more frequent sessions and adjusting over time based on response and stability.
- Early response within the first 4–6 weeks helps clinicians determine whether ketamine is moving symptoms in a meaningful, sustainable direction.
- Real-world VA data shows that a subset of patients reach response or remission within weeks, followed by less frequent maintenance dosing.
- FDA-labeled esketamine schedules include built-in reassessment points, reinforcing that duration is guided by outcomes, not a fixed endpoint.
- Monitoring requirements, including post-dose observation and vital sign checks, directly affect appointment length and overall treatment planning.
- Ketamine is most effective when used as part of a broader psychiatric care plan, not as a one-time intervention.
Citations
- U.S. Department of Veterans Affairs. Clinical Outcomes of Intravenous Ketamine for Depression in the VA Health System.
https://www.psychiatrist.com/jcp/clinical-outcomes-intravenous-ketamine-for-depression-va-health-system/ - U.S. Food and Drug Administration. SPRAVATO® (esketamine) Prescribing Information, 2025.
https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/211243s016lbl.pdf
