title: Continuation phase intravenous ketamine in adults with treatment-resistant depression.
abstract: Little is known about the antidepressive effects of repeated intravenous ketamine infusions beyond the acute phase of treatment in patients with refractory depression.
  
  
  
  Twelve subjects with treatment-resistant non-psychotic unipolar or bipolar major depression and suicidal ideation were given repeated (up to 6) thrice-weekly acute-phase intravenous infusions of ketamine (0.5mg/kg, administered over 100min). Those who remitted during acute-phase treatment received continuation-phase treatment that consisted of 4 weekly ketamine infusions, followed by 4 weeks of post-continuation phase follow-up (during which no further ketamine infusions were administered). Clinical measures were assessed at baseline, at 24h following each infusion, at the last acute-phase observation, and during continuation and post-continuation follow-up (acute phase remitters only).
  
  
  
  Of the 12 enrollees, 5 (41.7%) remitted and 7 (58.3%) responded to ketamine treatment during the acute-phase. All five subjects who remitted during the acute-phase experienced further depressive symptom improvement during continuation-phase treatment. Four subjects lost remission status during the post-continuation phase, but all were still classified as positive treatment responders at the end of the post-continuation phase. Adverse effects were generally mild and transient during acute- and continuation-phase treatment; however, one subject developed behavioral outbursts and suicide threats during follow-up while hospitalized, and one subject died by suicide several weeks after the end of follow-up.
  
  
  
  This was an uncontrolled feasibility study with a small sample size.
  
  
  
  The continuation-phase administration of ketamine at weekly intervals to patients with treatment-resistant depression who remitted during acute-phase ketamine treatment can extend the duration of depressive symptom remission. The antidepressive effect of ketamine persisted for several weeks after the end of continuation-phase treatment. Our results highlight the need for close monitoring of subjects who are at high baseline risk for suicide but do not respond clinically to ketamine. CLINICALTRIALS.
  
  
  
  NCT02094898.
authors.affiliation: Department of Psychiatry & Psychology, Mayo Clinic Depression Center, Mayo Clinic, Rochester, MN, USA.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Vande Voort
authors.affiliation: Department of Psychiatry & Psychology, Mayo Clinic Depression Center, Mayo Clinic, Rochester, MN, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Morgan
authors.affiliation: Department of Psychiatry & Psychology, Mayo Clinic Depression Center, Mayo Clinic, Rochester, MN, USA.
authors.forename: Simon
authors.initials: S
authors.lastname: Kung
authors.affiliation: Department of Psychiatry & Psychology, Mayo Clinic Depression Center, Mayo Clinic, Rochester, MN, USA.
authors.forename: Keith G
authors.initials: KG
authors.lastname: Rasmussen
authors.affiliation: Department of Psychiatry & Psychology, Mayo Clinic Depression Center, Mayo Clinic, Rochester, MN, USA.
authors.forename: Jose
authors.initials: J
authors.lastname: Rico
authors.affiliation: Department of Psychiatry & Psychology, Mayo Clinic Depression Center, Mayo Clinic, Rochester, MN, USA.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Palmer
authors.affiliation: Department of Psychiatry & Psychology, Mayo Clinic Depression Center, Mayo Clinic, Rochester, MN, USA.
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Schak
authors.affiliation: Department of Psychiatry & Psychology, Mayo Clinic Depression Center, Mayo Clinic, Rochester, MN, USA.
authors.forename: Susannah J
authors.initials: SJ
authors.lastname: Tye
authors.affiliation: Department of Anesthesia, Mayo Clinic, Rochester, MN, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Ritter
authors.affiliation: Department of Psychiatry & Psychology, Mayo Clinic Depression Center, Mayo Clinic, Rochester, MN, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Frye
authors.affiliation: Department of Psychiatry & Psychology, Mayo Clinic Depression Center, Mayo Clinic, Rochester, MN, USA. Electronic address: bobo.william@mayo.edu.
authors.forename: William V
authors.initials: WV
authors.lastname: Bobo
mesh_terms: D000328:Adult; D000928:Antidepressive Agents / Q000627:therapeutic use*; D001714:Bipolar Disorder / Q000188:drug therapy*; D003865:Major Depressive Disorder / Q000188:drug therapy*; D061218:Depressive Disorder, Treatment-Resistant / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007649:Ketamine / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D012074:Remission Induction; D018401:Sample Size; D059020:Suicidal Ideation; D055815:Young Adult
chemical_list: D000928:Antidepressive Agents; D007649:Ketamine
keywords: Bipolar depression; Continuation; Depression; Ketamine; Major depression; Repeated; Treatment resistant