The effectiveness of intravenous ketamine in adults with treatment-resistant major depressive disorder and bipolar disorder presenting with prominent anxiety: Results from the Canadian Rapid Treatment Center of Excellence

J Psychopharmacol. 2021 Feb;35(2):128-136. doi: 10.1177/0269881120954048. Epub 2020 Oct 11.


Background: Individuals meeting criteria for treatment-resistant depression (TRD) are differentially affected by high levels of anxiety symptoms.

Aims: There is a need to identify the efficacy of novel rapid-onset treatments in adults with mood disorders and comorbid anxious-distress.

Methods: This study included patients with treatment-resistant major depressive disorder (MDD) or bipolar disorder (BD) who were receiving intravenous (IV) ketamine treatment at a community-based clinic.Anxious-distress was proxied using items from the Quick Inventory of Depressive Symptomatology-Self Report 16-item (QIDS-SR16) and Generalized Anxiety Disorder 7-item (GAD7) scales. The difference in QIDS-SR16 total score, QIDS-SR16 suicidal ideation (SI) item and GAD7 score were analyzed between groups.

Results: A total of 209 adults with MDD (n = 177) and BD (n = 26) were included in this analysis. From this sample, 94 patients (mean = 45 ± 13.9 years) met the criteria for anxious-distress. Individuals meeting the criteria for anxious-distress exhibited a significantly greater reduction in QIDS-SR16 total score following four infusions (p = 0.02) when compared with patients not meeting the anxious-distress criteria. Both anxious-distressed and low-anxiety patients exhibited a significant reduction in SI (p < 0.0001) following four infusions.Finally, there was a significantly greater reduction in anxiety symptoms in the anxious-distress group compared with the non-anxious distress group following three (p = 0.02) and four infusions (p < 0.001).

Conclusion: Patients with TRD and prominent anxiety receiving IV ketamine exhibited a significant reduction in depressive, SI and anxiety symptoms.

Keywords: Ketamine; anxiety; bipolar disorder; distress; major depressive disorder; treatment-resistant depression.

MeSH terms

  • Administration, Intravenous / methods
  • Adult
  • Anxiety / drug therapy*
  • Anxiety Disorders / drug therapy*
  • Bipolar Disorder / drug therapy*
  • Canada
  • Depressive Disorder, Major / drug therapy*
  • Depressive Disorder, Treatment-Resistant / drug therapy*
  • Female
  • Humans
  • Infusions, Intravenous / methods
  • Ketamine / therapeutic use*
  • Male
  • Middle Aged
  • Psychiatric Status Rating Scales
  • Self Report
  • Suicidal Ideation


  • Ketamine