How Many Ketamine Sessions Do You Need for Depression?

There is no standard course, but the trials patients tend to read about give a sense of the range. Their initial courses ran from about two to four weeks, with sessions two or three times a week:

In the trials above, initial courses were given two or three times a week. When one trial compared those two rhythms directly, twice-weekly and thrice-weekly dosing kept depressive symptoms similarly improved over about two weeks, so in that study the extra weekly session added no clear benefit.

After an initial course, sessions are sometimes spaced further apart. In the 2019 trial, people who had responded moved to once-weekly sessions for four weeks, and on average their symptom scores held steady during that phase.

Because a single dose tends to wear off. In a 2006 placebo-controlled trial in treatment-resistant depression, improvement began within about two hours of one intravenous dose, but only about a third of those treated still met the response criteria a week later.

Repeated doses appear to build on each other for some people. A 2020 meta-analysis of randomized trials found that repeated ketamine kept the early improvement going, and in the 2019 trial the share of participants who responded roughly doubled over a course of six infusions compared with a single one.

It varies widely. In the 2019 trial, the people who reached the response threshold needed a median of three infusions to get there, which means some responded sooner and others later. About four in ten never met it during the course.

Researchers have also found that early change can be informative. In the 2013 trial of six infusions, whether someone had already responded four hours after the first infusion strongly predicted whether they would be a responder by the end, though it was not a perfect predictor.

Individually, and it is revisited along the way. Typical plans here involve a series of sessions spread over several weeks. The supervising clinician calculates each dose for you, and after the series we look together at how you have responded.

From there the plan can go one of three ways: continue, space sessions further apart, or stop. If treatment is not helping, stopping is a legitimate outcome, not a failure. You get the full cost of any recommended course in writing before you commit to it, and with your permission we keep your psychiatrist, therapist, or physician informed. Follow-up conversations can happen by telehealth as long as you are physically in Florida.

Nobody has worked out the ideal number of sessions, the best spacing, or how long to continue. An expert consensus statement from the American Psychiatric Association's research council pointed to small study sizes and a lack of longer-term data, and a systematic review of side effects found little assessment of safety after repeated or long-term dosing. That uncertainty is the main reason a plan should be reviewed regularly rather than sold as a fixed package.