Rapid effectiveness of intravenous ketamine for ultraresistant depression in a clinical setting and evidence for baseline anhedonia and bipolarity as clinical predictors of effectiveness
Abstract
BACKGROUND:
Intravenous ketamine has been established as an efficacious and safe treatment, with transient effect, for treatment-resistant depression. However, the effectiveness of intravenous ketamine in non-research settings and with ultraresistant depression patients remains understudied.
AIMS:
This study aims to measure the response and remission rates in ultraresistant depression patients in a clinical setting by means of a retrospective, open label, database study. Secondarily, the study will attempt to support previous findings of clinical predictors of effectiveness with intravenous ketamine treatment.
METHODS:
Fifty patients with ultraresistant depression were treated between May 2015-December 2016, inclusive, in two community hospitals in Edmonton using six ketamine infusions of 0.5 mg/kg over 40 min over 2-3 weeks. Data were collected retrospectively from inpatient and outpatient charts. Statistical analysis to investigate clinical predictors of effectiveness included logistic regression analysis using a dependent variable of a 50% reduction in rating scale score at any point during treatment.
RESULTS:
At baseline, the average treatment resistance was severe, with a Maudsley Staging Method score of 12.1 out of 15, 90.0% were resistant to electroconvulsive therapy, and the average Beck Depression Inventory score was 34.2. The response rate was 44% and remission rate was 16%. As a single predictor, moderate or severe anhedonia at baseline predicted a 55% increased likelihood of response. As a combined predictor, this level of anhedonia at baseline with a diagnosis of bipolar depression predicted a 73% increase in likelihood of response.
CONCLUSION:
In a clinical setting, intravenous ketamine showed effectiveness in a complex, severely treatment-resistant, depressed population on multiple medication profiles concurrently. This study gave support to anhedonia and bipolar depression as clinical predictors of effectiveness.
Thomas, R. K., Baker, G., Lind, J., & Dursun, S. (2018). Rapid effectiveness of intravenous ketamine for ultraresistant depression in a clinical setting and evidence for baseline anhedonia and bipolarity as clinical predictors of effectiveness. Journal of psychopharmacology, 32(10), 1110-1117., 10.1177/0269881118793104
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