Antidepressant medications have revolutionized the treatment of depression, but most currently available medications do not begin to work for several weeks. A treatment that could relieve the symptoms without the relatively long wait has been on researchers' wish lists for some time and it now appears as if it may have arrived. Reporting in the Archives of General Psychiatry, researchers from the National Institute of Mental Health say that a single intravenous shot of a drug known as ketamine, which is a general anesthetic agent, appears to relieve the symptoms of depression within two hours and remains effective for up to one week.
The research was led by Carlos A. Zarate Jr., M.D., who studied the effects of ketamine in 12 women and six men with an average age 47 years. Two hours after the injection of ketamine, the patients showed significant improvement and the effect lasted through the following week. "To our knowledge, there has never been a report of any other drug or somatic treatment that results in such a dramatic rapid and prolonged response within a single administration," the researchers wrote.
Nearly all currently available antidepressants work by increasing the levels of chemicals in the brain known as monoamines, including serotonin and dopamine. Over time, this accumulation of chemicals acts to improve a patient's mood. However, ketamine directly targets a different brain pathway - the glutamatergic system, involved in learning and memory. "This line of research holds considerable promise for developing new treatments for depression with the potential to alleviate much of the morbidity and mortality associated with the delayed onset of action of traditional antidepressants," the researchers concluded.
Source: Archives of General Psychiatry
