RESIDENT: Rapid effectiveness of intravenous ketamine for ultraresistant depression in a clinical setting and evidence for baseline anhedonia as a clinical predictor of effectiveness

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Presenting Author(s): Rejish K. Thomas

Co-Author(s): Glen B. Baker, Serdar Dursun, John Lind

Date and time: 24 Mar 2018 from 14:15 to 14:30

Location: Bluebell  Floor Map

Learning Objectives:

  1. To present findings from a local, retrospective, open label, database study on intravenous ketamine for ultraresistant depression
  2. To investigate the response rate of intravenous ketamine and clinical predictors of effectiveness in this study and in the literature
  3. To discuss future directions in clinical and in research settings for ketamine as an antidepressant

Literature References:

Abdallah CG, Adams TG, Kelmendi B, et al. (2016) Ketamine's mechanism of action: a path to rapid-acting antidepressants. Depression and Anxiety 33(8): 689–697.

Abdallah CG, Averill LA, Collins KA, et al. (2017) Ketamine treatment and global brain connectivity in major depression. Neuropsychopharmacology: Official Publication of the American College of Neuropsychopharmacology 42(6): 1210–1219.

Coyle CM and Laws KR (2015) The use of ketamine as an antidepressant: a systematic review and meta-analysis. Human Psychopharmacology 30(3): 152–163.

Duman RS (2014) Pathophysiology of depression and innovative treatments: remodeling glutamatergic synaptic connections. Dialogues in Clinical Neuroscience 16(1): 11–27.

Lally N, Nugent AC, Luckenbaugh DA, et al. (2014) Anti-anhedonic effect of ketamine and its neural correlates in treatment-resistant bipolar depression. Translational Psychiatry 4: e469.

 Sanacora G, Frye MA, McDonald W, et al. (2017) A consensus statement on the use of ketamine in the treatment of mood disorders. JAMA psychiatry 74(4): 399–405.

 Wilkinson ST, Ballard ED, Bloch MH, et al. (2017) The effect of a single dose of intravenous ketamine on suicidal ideation: a systematic review and individual participant data meta-analysis. American Journal of Psychiatry: appiajp201717040472.


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 and December 2016, inclusive, in two community hospitals in Edmonton using six ketamine infusions of 0.5mg/kg over forty minutes over two to three 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 MSM score of 12.1 out of 15, 90.0% were resistant to ECT, and the average BDI 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.

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 as a clinical predictor of effectiveness.

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