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

Summary & key facts

Researchers gave 20 people with severe, treatment-resistant generalized or social anxiety weekly ketamine injections under the skin for three months. Anxiety ratings dropped by about half one hour after dosing, and 18 people said their social or work life improved. Short-term side effects included nausea, dizziness, blurred vision, and a temporary blood pressure rise of about 10 mm Hg. Dissociative effects (feeling disconnected or strange) became milder with repeated doses. Because this was a small study with no comparison group and it only included people who had already shown a response to ketamine, the results are promising but not definitive.

Key facts:

• Twenty people with treatment-resistant generalized anxiety disorder or social anxiety disorder received ketamine injections under the skin once or twice a week for three months.
• One hour after each dose, anxiety scores fell by about half compared with before dosing.
• Eighteen of the 20 people reported improved social life or work functioning during the treatment period.
• Reported short-term side effects included nausea, dizziness, and blurred vision.
• Blood pressure rose by about 10 mm Hg at 30 minutes after dosing compared with before dosing.
• Feelings of dissociation or being disconnected were strongest early on and then declined over time, with a typical dissociation score falling from about 20 to about 9 by week 14.
• The study had no control group and only included people who had already responded to ketamine, so the findings suggest ketamine might help some people but need confirmation in larger, controlled studies.

Abstract

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: http://www.anzctr.org.au/ACTRN12615000617561.

Topics

Anxiety, Depression, Psychometrics, Treatment, Cognitive Processes Treatment of Major Depression Tryptophan and brain disorders

Categories

Health Sciences Medicine Pharmacology

Tags

Adverse effect Anesthesia Anxiety Astrobiology Blurred vision Dosing Generalized anxiety disorder Hamilton Anxiety Rating Scale Internal medicine Ketamine Medicine Nausea Physics Psychiatry Psychology Refractory (planetary science) Social anxiety Tolerability

Substances

Ketamine

Conditions & symptoms

Anxiety Anxiety or worry Feeling disconnected from others