title: A 12-month naturalistic observation of three patients receiving repeat intravenous ketamine infusions for their treatment-resistant depression.
abstract: BACKGROUND
  Acute administration of subanesthestic doses of intravenous ketamine have been shown to elicit a rapid antidepressant response in patients with treatment-resistant depression. However, it remains to be seen if repeated doses over a longer period of time will have the same effects. Here, we assess the long-term efficacy of repeated intravenous ketamine infusions in three patients with high treatment-resistant depression via a naturalistic observation study.
  
  
  METHODS
  Three patients consented to intravenous ketamine infusions as a therapy for their treatment-resistant depression. Patients were administered ketamine at 0.5mg/kg of ideal body weight over 40 min followed by a saline flush until discharge. Severity of depressive symptoms was rated with the Montgomery-Asberg Depression Rating Scale.
  
  
  RESULTS
  All three patients responded to the ketamine infusions, but each went through an individualized course of treatment based on their own response.
  
  
  CONCLUSIONS
  This was an open-label naturalistic observation without blinding, randomization, or a placebo control.
  
  
  CONCLUSIONS
  These cases add to the literature supporting the therapeutic effect of low-dose repeated intravenous ketamine for patients with treatment-resistant depression. Further study is needed to define the risks, benefits, indications, and contraindications of this potential treatment.
authors.affiliation: Department of Clinical and Health Psychology, University of Florida, Gainesville, FL 32610, USA.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Szymkowicz
authors.forename: Nora
authors.initials: N
authors.lastname: Finnegan
authors.forename: Roman M
authors.initials: RM
authors.lastname: Dale
mesh_terms: D000328:Adult; D000928:Antidepressive Agents / Q000008:administration & dosage*; D003865:Major Depressive Disorder / Q000188:drug therapy*; D061218:Depressive Disorder, Treatment-Resistant / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007649:Ketamine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged
chemical_list: D000928:Antidepressive Agents; D007649:Ketamine