Ketamine given intravenously rapidly reduces depressive symptoms, with effects lasting at least a week. In an analysis of 17 randomized controlled trials with 809 participants, the benefit over placebo was larger for patients who had already failed two or more prior antidepressant trials. However, no patient-level clinical or demographic characteristics—such as age, sex, or diagnosis—could predict who would respond best, limiting the ability to personalize ketamine prescriptions. The findings confirm ketamine's broad effectiveness for depression but show that precision medicine approaches cannot yet guide treatment decisions.
Adding mindfulness, music, and a light-occluding eye mask during ketamine infusion for depression did not improve antidepressant effects compared to ketamine alone, but it enriched the subjective experience. Participants in the combined sensory intervention group reported deeper engagement, a stronger sense of connection to reality, increased focus, moments of relief from sadness, and feelings of awe and spiritual insight. However, four individuals in that group reported discomfort. The findings suggest that while the sensory interventions make the experience more meaningful for many, they may cause discomfort for a few, and making them optional could avoid this.