Researchers from Stanford University in the United States explored whether a single dose of ketamine can lift mood in people with depression, comparing its effects to a saline placebo infusion. The study, published in Nature Mental Health, raises questions about how effective ketamine truly is for mood improvement and suggests that the outcome may resemble a placebo response in some settings.
Ketamine first emerged in the medical field during the 1960s as a safe and rapid option for relief in emergency departments, particularly for pain and acute stress. Over the last decade, interest in its potential as an antidepressant has grown. Animal studies showed mood benefits after a single dose in mice, while human trials have reported mixed results. Some participants experienced mood enhancement, but the overall strength and consistency of the evidence have remained debated.
In a recent trial designed to separate any mind-altering consequences of ketamine from other influences, researchers administered the drug to patients under anesthesia. One group received ketamine while the other received a saline solution that did not contain the active compound. The study used a double blind approach so neither the patient nor the medical staff knew which substance was given during the procedure.
Within days after anesthesia, mood scores improved in both groups, as measured by the Montgomery-Åsberg Depression Rating Scale. Earlier surgical studies helped ensure that the observed mood improvement was not simply a result of the surgery or the anesthesia itself. This finding points to a substantial placebo component in the observed mood changes, rather than a robust, direct antidepressant effect from ketamine in this context.
Some participants who believed they had received ketamine reported meaningful changes in life satisfaction and mood. Yet the overall results of the trial do not prove ketamine to be a foolproof treatment for depression. The observed benefits appear to be largely driven by expectations and belief in the treatment rather than a guaranteed pharmacological effect. This interpretation aligns with broader evidence that placebo responses can strongly influence mood outcomes in depression research.
Historical discussions about the safety of red meat or other broad health claims illustrate how public perception can diverge from clinical data. In the case of ketamine and depression, cautious interpretation is warranted. Clinicians and researchers emphasize that while ketamine may hold value in specific contexts, its antidepressant efficacy is not uniformly proven across all patient groups or study designs. The current study adds to a growing body of literature that highlights the importance of carefully separating drug effects from expectations, setting, and the therapeutic environment when evaluating rapid-acting antidepressants.