By Laura Sanders Web edition : Wednesday, June 15th, 2011
The anesthetic ketamine works against depression by quickly boosting levels of a brain compound that has been linked to the condition, a new study in mice shows. The research may lead to highly effective and fast-acting antidepressants that provide relief within hours instead of weeks, scientists report online June 15 in Nature.
Traditional antidepressants can be effective but often take weeks or months to improve symptoms. “You can control malignant hypertension within minutes; a bad increase in blood sugar, bad migraines, asthma attacks, within minutes,” says psychiatrist Carlos Zarate of the National Institute of Mental Health in Bethesda, Md. “Yet why in psychiatry should we be satisfied with, ‘Just hang on for a few weeks or a few months, and you’re going to get better?’ That’s not acceptable in my mind.”
The new study may point to faster alternatives, Zarate says: “Here is increasing evidence that you can go more directly at the target, and that’s maybe why you get more of a rapid antidepressant effect.”
Mice receiving a single injection of ketamine showed fewer signs of depression just half an hour after the shot, and they continued to show multiple signs of reduced depression for a week, researchers at the University of Texas Southwestern Medical Center at Dallas found. For example, after one dose of ketamine, mice struggled longer to stay afloat in a beaker of water instead of giving up and sinking.
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http://www.sciencenews.org/view/generic/id/331258/title/Ketamine’s_antidepressant_effect_explained_