There are many medications available to treat depression. Depending on the person and type of depression, all the currently available anti depressants are said to be potentially effective. However, in almost all cases it takes anywhere from two to six weeks to observe a clinical response. For many patients this waiting time can be agonizing, especially if they have an acute depressive disorder with suicidal ideations.
Now there is research that has shown that the anesthetic drug Ketamine may have very rapid anti depressant effects. Early work by Rebecca Price and her colleagues (1) revealed that Ketamine acutely reduced suicidal thoughts when patients were assessed 24 hours after a single infusion of the drug. Even more significant was that the decrease in suicidal thoughts was maintained when the patients received repeated doses over the next 14 days. If these intriguing findings do hold up in clinical trials, then IV Ketamine may be an ideal treatment for patients who are at high risk for suicide. This may help overcome the time period while waiting for a conventional anti depressant to take effect.
As to how Ketamine produces such a rapid response is not well understood, but another group of researchers from UT Southwestern Medical Center have shed more light on the drug. The work by Dr. Lisa Monteggia, Associate Professor in Psychiatry, revealed that Ketamine produces anti depressant effects at very low doses and can be used in the emergency room in high-risk patients (2).
Monteggia said the next step is to investigate the short and long term effects of Ketamine and how the drug interacts in the brain cells. While all this does sound great, the use of Ketamine does have drawbacks. Ketamine is a potent NMDA receptor antagonist and has been widely used in general anesthesia for many years. What has been observed is that patients coming out of anesthesia also tend to develop changes in perception and impairment in cognition. The few clinical studies on Ketamine’s anti depressant benefits have not looked at these adverse effects yet.
Sources
1. Rebecca B. Price, Matthew K. Nock, Dennis S. Charney, and Sanjay J. Mathew. Effects of Intravenous Ketamine on Explicit and Implicit Measures of Suicidality in Treatment-Resistant Depression. Biological Psychiatry, 2009; 66 (5): 522 http://www.ncbi.nlm.nih.gov/pubmed?term=Rebecca%20B.%20Price%2C%20Matthew%20K.%20Nock%2C%20Dennis%20S.%20Charney%2C%20and%20Sanjay%20J.%20Mathew.
2. Anita E. Autry, Megumi Adachi, Elena Nosyreva, Elisa S. Na, Maarten F. Los, Peng-fei Cheng, Ege T. Kavalali, Lisa M. Monteggia. NMDA receptor blockade at rest triggers rapid behavioral antidepressant responses. Nature. 2011 Jun 15; 475(7354):91-5.; http://www.ncbi.nlm.nih.gov/pubmed?term=Anita%20E.%20Autry%2C%20Megumi%20Adachi%2C%20Elena%20Nosyreva%2C%20Elisa%20S.%20Na%2C%20Maarten%20F.%20Los%2C%20Peng-fei%20Cheng%2C%20Ege%20T.%20Kavalali%2C%20Lisa%20M.%20Monteggia.%20NMDA%20receptor%20blockade%20at%20rest%20triggers%20rapid%20behavioural%20antidepressant%20responses.%20Nature%2C%202011%3B
Reviewed July 13, 2011
by Michele Blacksberg R.N.
Edited by Alison Stanton