In brief
- A randomized trial from Columbia University finds that ketamine increases next-morning cortisol levels in people with depression and suicidal ideation.
- The greater the spike, the more significant the improvement in suicidal thoughts the following day, though the association fell just short of standard statistical significance.
- The group receiving midazolam, the active control drug, showed no such hormonal rebound.
A team from the Columbia University Medical Center and the New York State Psychiatric Institute has found that a single ketamine infusion elevates next-morning cortisol in patients hospitalized for depression with active suicidal ideation, and that this surge correlates with a reduction in those thoughts hours later. The finding, published in the Journal of Affective Disorders, is exploratory, and the authors themselves urge caution before drawing firm conclusions.
How the study was conducted
The study included 63 adults voluntarily admitted for major depression with suicidal ideation, out of 80 originally recruited. Participants were randomized to receive either a low-dose ketamine infusion (0.5 mg/kg intravenously over 40 minutes) or midazolam as an active control at 0.02 mg/kg. Saliva samples were collected the morning before treatment and again 24 hours later. Each collection involved two extractions—one immediately upon waking and another 30 minutes later—following a strict fasting and oral hygiene protocol to avoid contaminating the measurements.
What was found
In the ketamine group, cortisol levels upon waking rose clearly between the first and second morning; in the midazolam group, they decreased. Those who showed a greater rise in cortisol also tended to experience a more marked reduction in suicidal ideation, with an effect size that the authors describe as small to moderate, although the correlation did not reach statistical significance by conventional criteria. Furthermore, the cortisol rebound was not related to the degree of general depression improvement: it appears to be a phenomenon more linked to the suicidal component than to mood. A detail the researchers emphasize is the timing: the spike occurs many hours after the acute dissociative effects of ketamine have dissipated, which usually fade within an hour, suggesting a distinct and delayed biological mechanism.
What it implies
The most prudent interpretation is that this is a lead, not proof. The sample size is small, the analysis is exploratory, and the authors themselves do not know if higher cortisol helps ketamine work or if it merely accompanies the improvement without causing it; they also did not control for sleep quality that night, a limitation they acknowledge. Even so, the idea that a temporary reset of the stress axis plays a role in how ketamine calms a suicidal crisis aligns with years of research on cortisol and depression, opening the door to whether this reset could one day be used as a marker of response. For those already using ketamine, whether by prescription or otherwise, the data changes nothing in practice today: harm reduction still requires the same standard of care, with medical supervision in clinical settings and special attention when suicidal ideation is involved.
Source
- Tse-Hwei Choo et al. Increased morning cortisol after ketamine treatment for suicidal depression: exploratory report from a randomized trial. Journal of Affective Disorders / Medical Xpress, August 7, 2026.
Educational content written from a harm reduction perspective and with respect for individual freedom. It is not a substitute for advice from a healthcare professional and is not intended to encourage or condemn any drug use.
