Safety and efficacy of maintenance ketamine treatment in patients with treatment-refractory generalised anxiety and social anxiety disorders

J Psychopharmacol. 2018 Jun;32(6):663-667. doi: 10.1177/0269881118762073. Epub 2018 Mar 21.


Objective: In this maintenance treatment study, we sought to evaluate the effect on anxiety ratings, safety and tolerability of 3 months of weekly ketamine in 20 patients with treatment-refractory DSM IV generalised anxiety disorder (GAD) and/or social anxiety disorder (SAD), and subsequent assessment of remission post-treatment.

Methods: This was an uncontrolled open-label study in 20 patients who had been responders in an ascending dose ketamine study. The study was undertaken in a university clinic. Patients received one or two weekly ketamine doses of 1 mg/kg injected subcutaneously for 3 months. Data were collected from December 2015-June 2017.

Results: There were 10 women (50%) and 10 men (50%); 15 patients (75%) met criteria for GAD and 18 (90%) for SAD. One hour after dosing, Fear Questionnaire ratings decreased by ~50%, as did Hamilton Anxiety ratings. Clinician Administered Dissociative States Scale mean scores declined over time, from 20 points at week 1 to 8.8 points at week 14. Compared with pre-dose values, mean systolic and diastolic blood pressure increased by ~10 mm Hg at 30 min. The most common adverse events were nausea, dizziness and blurred vision. Of the 20 patients, 18 reported improved social functioning and/or work functioning during maintenance treatment.

Conclusions: Weekly ketamine dosing was safe and well tolerated, and post-dose dissociative symptoms tended to reduce after repeated dosing. Patients reported marked improvements in functionality and in their personal lives. Maintenance ketamine may be a therapeutic alternative for patients with treatment refractory GAD/SAD.

Trial registration:

Keywords: Ketamine; generalised anxiety disorder; maintenance treatment; social anxiety disorder.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Anti-Anxiety Agents / administration & dosage*
  • Anti-Anxiety Agents / adverse effects
  • Anxiety Disorders / drug therapy*
  • Anxiety Disorders / physiopathology
  • Drug Resistance
  • Female
  • Humans
  • Injections, Subcutaneous
  • Ketamine / administration & dosage*
  • Ketamine / adverse effects
  • Male
  • Middle Aged
  • Phobia, Social / drug therapy*
  • Phobia, Social / physiopathology
  • Surveys and Questionnaires
  • Treatment Outcome
  • Young Adult


  • Anti-Anxiety Agents
  • Ketamine

Associated data

  • ANZCTR/ACTRN12615000617561