Ketamine for major depressive disorder during an inpatient psychiatric admission: Effectiveness, adverse events, and...

Most studies examining the efficacy of ketamine for Major Depressive Disorder (MDD) have been conducted in outpatient or mixed inpatient/outpatient settings. Less is known about effectiveness and tolerability of ketamine for psychiatrically hospitalized patients. Efficacy and tolerability data from a naturalistic sample of acute inpatients may help inform institutions considering ketamine therapy for inpatient services.

We performed a retrospective chart review of inpatients with non-psychotic MDD treated during the initial 3 years of a ketamine infusion program. Treatment effectiveness was defined using change in Montgomery Asberg Depression Rating Scale (MADRS) scores over five infusions. MDD treatment response was defined by a 50 % reduction of MADRS score, and remission was defined as MADRS score ≤ 10 at any point during the treatment. We also report the frequency of adverse events.

41 patients with MDD were treated and had outcome data. 19 patients (46.5 %) met criteria for response and 15 patients (26.5 %) met criteria for remission during treatment. Four patients (10 %) had adverse psychological or behavioral outcomes.

MADRS scales were administered by psychiatrists, psychologists, and trainees in each discipline who did not undergo standardized training in scale administration. Consistent data regarding the race/ethnicity of the patients was not available.

Twice weekly racemic ketamine infusion is an effective treatment option for patients hospitalized with MDD. Unmonitored or at home ketamine therapy may pose substantial risks.