Ketamine fights depression, so does vitamin D
Yale University researchers have found a new pathway that explains why the antidepressant ketamine works to relieve depressive symptoms in a matter of hours instead of weeks or months, which is typical of other antidepressants.
The study reported in the August 20, 2010 issue of the journal Science indicates that theses findings should speed up the development of a safe and easy-to-administer form of the antidepressant ketamine, which is effective in treating severe depression, but needs to be delivered intravenously by medical professionals.
The traditional form of ketamine, even though effective at relieving depression, when taken by itself, it can lead to short-term psychotic symptoms. It is also used as a recreational or club drug known as "Special K" or simply "K".
Ronald Duman, professor of psychiatry and pharmacology at Yale, colleagues George Aghajanian and others mapped the molecular action of ketamine in the prefrontal cortex of rats and discovered that the drug, traditionally also used as an anesthetic for children, acts on a pathway that quickly forms new synaptic connections between neurons.
Specifically, the researchers identified a critical point in the pathway, Mammalian target of rapamycin or simply mTOR, which is required to control protein synthesis for the new synaptic connections.
Still, no one knows for sure when an effective form of ketamine can be developed. Ketamine can cause side effects, including blurred vision, confusion, drowsiness, increased or decrease blood pressure or heart beat, metal or mood changes, nausea, vomiting and nightmares.
Those who can't wait for drug companies to develop an effective and safe antidepressant may want to consider trying supplementation of vitamin D, which evidence suggests boosts depression risk when it is insufficient or deficient.
Stewart R. and Hirani V from King's College London and University College London Medical School in the United Kingdom published in the July 1, 2010 issue of Psychosomatic Medicine saying depressive symptoms in older people were linked with clinical vitamin D deficiency defined as having 25(OH)D levels lower than 10 ng/mL.
Another study led by May H.T. and colleagues from Intermountain Medical Center in Murray, UT and published in the June 2010 issue of American Heart Journal indicates that vitamin D levels are associated with incident depression among people aged 50 or older who had cardiovascular disease, but no prior history of depression.
Still another study led by Milaneschi Y. and colleagues at the National Institute on Aging in Baltimore MD and published in the July 2010 issue of Journal of Clinical Endocrinology and Metabolism found that low vitamin D is a risk factor for depression in older people.
Depression affects an estimated 17.5 million men and women in the United States, 9.2 million of whom have major or clinical depression. The condition costs Americans $30.4 billion in economic loss.
By Jimmy Downs and editing by Rachel Stockton