Antidepressant effects of ketamine in depressed patients

Summary & key facts

In a small, carefully controlled study, seven people with major depression each received a single low-dose ketamine infusion on one day and a saline infusion on another day, without anyone knowing which was which. People who got ketamine showed clear improvement in their depressive symptoms within three days, while those who got saline did not. The study suggests drugs that block the NMDA receptor in the brain might have rapid antidepressant effects, but it was tiny and short, so it does not prove ketamine is safe or effective as a regular treatment.

Key facts:

• Seven people with major depression completed a randomized, double-blind test where each person received both a ketamine infusion and a saline infusion on different days so neither they nor the researchers knew who got which treatment at the time.
• The active treatment was a single low dose of ketamine given by vein, about half a milligram per kilogram of body weight.
• Within three days after ketamine, standard depression scores on a 25-item scale fell by about 14 points on average, while scores did not change after the saline infusion.
• This was the first placebo-controlled, double-blind trial testing an NMDA receptor blocker for depression, suggesting that blocking this brain receptor could play a role in reducing depressive symptoms.
• The study was very small and only looked at short-term effects after one dose, so it cannot show whether benefits last, how often treatment would be needed, or whether it is safe over time.
• For people, the result means ketamine might reduce depressive symptoms quickly in some cases, but this single early study is not enough to recommend ketamine as a routine or long-term treatment.

Topics

Functional Brain Connectivity Studies Treatment of Major Depression Tryptophan and brain disorders

Categories

Health Sciences Medicine Pharmacology

Tags

Alternative medicine Anesthesia Antagonist Antidepressant Behavioural despair test Depression (economics) Developmental psychology Economics Glutamate receptor Hippocampus Internal medicine Ketamine Ketamine hydrochloride Macroeconomics Medicine NMDA receptor Pathology Pathophysiology Placebo Psychology Randomized controlled trial Rating scale Receptor Saline

Substances

Ketamine

Conditions & symptoms

Depression Sadness or low mood