Source: Alice G. Walton, Forbes
The study, carried out at the Columbia University Medical Center and the New York State Psychiatric Institute, looked at 80 patients with clinical depression. They all had suicidal thoughts that were intrusive enough to fall into the category of clinical suicidal ideation. The participants were randomized to receive a low-dose infusion of either ketamine or midazolam, a sedative; they were followed for six weeks, during which time the participants all received usual psychiatric care. To measure their depressive symptoms and suicidal ideation (thoughts or urges), the participants filled out questionnaires, like the Scale for Suicidal Ideation and the Beck Depression Inventory.
Within 24 hours, the participants who’d received ketamine reported significant changes in symptoms compared to those receiving midazolam. They had a reduction in suicidal thoughts, depressive symptoms, and fatigue. In fact, the participants who didn’t respond to midazolam were later given ketamine, and they showed the same improvements.
And these changes seemed to last for up to six weeks. The side-effects, which were mainly dissociation—a sense of detachment—and increased blood pressure, resolved within minutes or hours after the ketamine injection.
When the researchers teased apart the variables, they found that the reduction in depressive symptoms accounted for only a third of the reduction in suicidal thoughts, which suggests that ketamine’s effects on suicidality comes from more than just a reduction in depression. What that might be still needs to be explored.