There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
Intravenous ketamine has shown rapid antidepressant effects in early trials, making
it a potentially attractive candidate for depressed patients at imminent risk of suicide.
The Implicit Association Test (IAT), a performance-based measure of association between
concepts, may have utility in suicide assessment.
Twenty-six patients with treatment-resistant depression were assessed using the suicidality
item of the Montgomery-Asberg Depression Rating Scale (MADRS-SI) 2 hours before and
24 hours following a single subanesthetic dose of intravenous ketamine. Ten patients
also completed IATs assessing implicit suicidal associations at comparable time points.
In a second study, nine patients received thrice-weekly ketamine infusions over a
12-day period.
Twenty-four hours after a single infusion, MADRS-SI scores were reduced on average
by 2.08 points on a 0 to 6 scale (p < .001; d = 1.37), and 81% of patients received
a rating of 0 or 1 postinfusion. Implicit suicidal associations were also reduced
following ketamine (p = .003; d = 1.36), with reductions correlated across implicit
and explicit measures. MADRS-SI reductions were sustained for 12 days by repeated-dose
ketamine (p < .001; d = 2.42).
These preliminary findings support the premise that ketamine has rapid beneficial
effects on suicidal cognition and warrants further study.