People with depression who had a reduction in suicidal thoughts after a single ketamine infusion also showed less nighttime wakefulness, measured by EEG, the night after the infusion compared to those whose suicidal thoughts did not improve. The level of wakefulness in responders was similar to that of healthy controls. This suggests that ketamine's effect on suicidal ideation may involve changes in sleep-wake regulation.
Ketamine rapidly reduces suicidal thoughts in major depressive disorder, but the effect is short-lived. In this trial, adults with major depression and active suicidal ideation received a single ketamine infusion, then were randomly assigned to take either low-dose buprenorphine or a placebo daily for four weeks. Suicidal thoughts dropped significantly more in the buprenorphine group (average decrease of 11.6 points on the Scale for Suicide Ideation) than in the placebo group (average decrease of 6.3 points). Depression scores did not differ between groups. No serious side effects occurred. Buprenorphine appears to sustain and boost ketamine's antisuicidal effects, offering a potentially safe, scalable option for suicide prevention.