Antidepressant effects of ketamine in depressed patients
(Historical context record — retained to show where the field started, not as actionable evidence.)
Reasonable evidence with real limitations. how we score evidence
Caveat on this rating: N=7; included for historical significance only.
esketamine (Spravato) only — TRD 2019, monotherapy Jan 2025, REMS in force. Racemic ketamine is approved as an anesthetic; its psychiatric use is off-label.
Historical anchor: in 7 patients (double-blind crossover), a single IV ketamine infusion reduced Hamilton depression scores by a mean of 14 points within 72 hours vs no change on saline — the first controlled demonstration of rapid NMDA-pathway antidepressant effects, in a sample far too small for any clinical conclusion.
Worth asking
(Historical context record — retained to show where the field started, not as actionable evidence.)
Source
Antidepressant effects of ketamine in depressed patients — Berman RM, et al. (2000)
Reputable peer-reviewed journal
Read the source: https://doi.org/10.1016/s0006-3223(99)00230-9
DOI: 10.1016/s0006-3223(99)00230-9
How this was scored
- Study design
- Randomised controlled trial
- Funding
- Funding not disclosed
- Published in
- Reputable peer-reviewed journal
- Sample size
- 7
- Preregistered
- No
- Conflicts disclosed
- not recorded
- Independent of proponent
- not recorded
- Retracted
- No
Read the full scoring rubric, including what it can't tell you.
Published August 19, 2026.
Questions
How strong is the evidence behind this?
Resolv rates this source "moderate evidence". Reasonable evidence with real limitations. It scores 55 out of 100 on our published rubric. One caveat travels with that badge: N=7; included for historical significance only. The score is calculated from recorded facts about the source — study design, funding, publication venue, sample size, preregistration — not typed in by an editor.
What is the source for this?
Antidepressant effects of ketamine in depressed patients — Berman RM, et al. (2000). Published in: Reputable peer-reviewed journal. DOI: 10.1016/s0006-3223(99)00230-9. The full source is linked on this page so you can read it yourself.
Who paid for this research, and does that matter?
Study design: Randomised controlled trial. Funding: Funding not disclosed. Independence from the proponent is not recorded. Industry sponsorship is one of the most reliably measured biases in medicine, which is why funding carries real weight in the score rather than sitting in a footnote.
Is ketamine FDA approved for this use?
No. No FDA review of this evidence for this use has taken place. esketamine (Spravato) only — TRD 2019, monotherapy Jan 2025, REMS in force. Racemic ketamine is approved as an anesthetic; its psychiatric use is off-label.
Is this medical advice?
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.