“Ketamine significantly reduced SI and depression across the sample,” lead author Jessica R. Gilbert, MD, National Institute of Mental Health, and co-authors noted.
The study consisted of 29 drug-free participants with TRD, including 12 who had previously attempted suicide. Patients were experiencing a major depressive episode that lasted at least 4 weeks, were unresponsive to at least 1 medication during the episode, and scored 20 or higher on the Montgomery-Asberg Depression Rating Scale (MADRS).
Researchers collected magnetoencephalographic (MEG) data by having patients perform an attentional dot probe task with emotional face stimuli at baseline and then again several hours after ketamine infusion. Synthetic aperture magnetometry was used to project source power in the theta, alpha, beta, and gamma frequencies for angry-neutral, happy-neutral, and neutral facial expressions during a one-second period.
“Post-ketamine, attempters had improved accuracy and non-attempters had reduced accuracy on the task,” the authors found.
“The findings highlight key differences in band-limited power between attempters and non-attempters and reinforce previous findings that ketamine has distinct response properties in patients with a suicide history,” researchers concluded.