Effectiveness and safety of repeat dose subcutaneous ketamine for treatment-resistant depression, and the impact of prior ketamine treatment: open label extension of the KADS study
The British Journal of Psychiatry July 6, 2026 Nick Glozier, Richard W. Morris, Elizabeth Stratton et al.
A 4-week course of subcutaneous racemic ketamine produced short-term clinical benefit in a minority of people with treatment-resistant depression, with response rates declining substantially after treatment cessation. Among 130 participants, 30% responded at treatment end (Montgomery-Åsberg Depression Rating Scale reduction ≥50%), but only 17% remained responders 4 weeks later, and over 50% experienced less than a 25% reduction in depression scores. No difference in response was found between fixed and flexible dosing regimens. Prior ketamine treatment during an earlier randomized trial did not affect later outcomes. No suicides or suicidal behavior requiring admission occurred, and only expected side effects were observed.