Standard IV Ketamine Infusion Protocols for Treatment-Resistant Depression

Depression treatment with ketamine may involve a series of intravenous infusions for some adults with treatment-resistant depression, but the dose, monitoring plan, and follow-up schedule must be determined by a qualified prescribing clinician. The commonly studied research regimen is 0.5 mg/kg delivered intravenously over 40 minutes. It is not a universal protocol, and ketamine injection is FDA-approved as an anesthetic, not specifically as an antidepressant.

For people considering treatment-resistant depression options, the practical questions are whether they are an appropriate candidate, how a clinic monitors safety, and how response is measured over time.

What is the standard IV ketamine research protocol?

Intravenous ketamine has been studied as a rapid-acting intervention for treatment-resistant depression, meaning depression that has not improved adequately after appropriate prior treatments. In an early randomized trial, Berman and colleagues reported rapid improvement in depressive symptoms after a single subanesthetic ketamine infusion in patients with major depression.

The regimen most often cited in clinical research is 0.5 mg/kg infused over 40 minutes. The Berman et al. study indexed by PubMed is one of the early studies associated with this approach. Research protocols and real-world clinical practices can differ, so readers should not treat a published regimen as personal dosing advice.

Ketamine is an NMDA receptor antagonist, a medicine that affects glutamate signaling in the brain. Learn more about the proposed biology in our guide to neuroplasticity and ketamine.

Who may be evaluated for IV ketamine?

Evaluation generally focuses on adults with moderate to severe major depressive disorder and a documented history of inadequate response to prior treatment. A useful treatment history includes medicines tried, doses, duration, response, side effects, and reasons for stopping treatment.

A clinician also needs to assess current symptoms and safety. This includes suicidal thinking, psychotic symptoms, bipolar-spectrum history, substance-use history, blood pressure and cardiovascular history, current medicines, and other medical conditions that could affect treatment planning. Ketamine can temporarily increase blood pressure and heart rate, which is why cardiovascular screening and monitoring matter.

The FDA-approved labeling for ketamine injection includes warnings and precautions relevant to its use as an anesthetic. Patients and clinicians can review the current product information through DailyMed's ketamine injection labeling. The label does not establish an antidepressant infusion protocol.

How an induction series is commonly structured

Published and clinic-based approaches often begin with a time-limited induction series rather than a single infusion. Six infusions over about two to three weeks, commonly scheduled two or three times weekly on nonconsecutive days, is a frequently used framework. The number of sessions and timing should remain individualized because response, tolerability, medical history, and access to follow-up vary.

Some clinicians may consider dose changes after reviewing benefit and side effects. That decision belongs to the treating team. A higher dose is not automatically a better dose, and dissociation, blood-pressure changes, nausea, and other effects may influence whether a protocol is continued or adjusted.

Response should be measured rather than assumed. Clinics may use the Patient Health Questionnaire-9, Quick Inventory of Depressive Symptomatology, or Montgomery-Asberg Depression Rating Scale. In depression research, response is often defined as at least a 50% reduction from baseline on a rating scale, while remission cutoffs depend on the instrument used. Suicidal ideation should be assessed separately with an appropriate validated method and urgent safety concerns require immediate clinical attention.

Our overview of how many ketamine treatments may be needed explains why treatment count is not the same as a guarantee of response.

What monitoring is expected during an infusion?

IV ketamine should be administered in a setting prepared to monitor and respond to acute changes. A typical setup includes baseline vital signs, a peripheral IV, repeat blood-pressure checks, heart-rate monitoring, pulse oximetry, trained staff, and equipment appropriate for emergency response.

The exact monitoring intervals, criteria for pausing an infusion, and discharge standards should follow the treating organization's policies and the clinician's assessment. The American Society of Anesthesiologists provides professional resources on anesthetic care and patient safety through its standards and practice parameters. These resources are useful context, but they do not replace an individualized psychiatric and medical evaluation.

During treatment, some people experience dissociation, altered perception, dizziness, nausea, or temporary increases in blood pressure. These effects often resolve as the infusion ends, but patients should tell staff promptly about distressing symptoms. See our patient-focused review of common ketamine side effects and our explanation of cardiovascular monitoring for additional context.

What happens after the induction series?

People who show meaningful improvement may discuss a maintenance plan with their clinician. Weekly treatment at first, followed by longer intervals when symptoms remain stable, is one approach used in practice. There is no single maintenance schedule that fits every patient, and longer-term repeated-exposure safety data are still developing.

Follow-up should include depression symptoms, suicidal ideation, daily functioning, side effects, blood pressure concerns, urinary symptoms, and changes in medicines or substance use. If benefits fade quickly, that is useful information for a treatment discussion, not a reason to self-adjust dose or frequency.

Medication review matters. Benzodiazepines and other medicines may affect sedation, monitoring, or clinical response, depending on the individual situation. Do not stop or hold a prescribed medicine without direction from the clinician managing it. Read more about ketamine and benzodiazepines and potential medication interactions.

How to compare an IV ketamine program

A careful program should be able to explain who performs the evaluation, what medical and psychiatric screening is used, how vital signs are monitored, what happens if symptoms worsen, how outcomes are measured, and how the patient gets home safely. Ask how the program coordinates with an existing psychiatrist, primary care clinician, or therapist when applicable.

It is also reasonable to ask what the program does not know. Evidence supports short-term antidepressant effects for some patients, while questions remain about the best maintenance schedule, durability for an individual patient, and long-term outcomes with repeated treatment. A responsible discussion should make those limits clear.