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The drug ketamine may sound vaguely familiar. Ketamine is used as an anesthetic but is also abused as "Special K," a recreational hallucinogen. Interestingly, recent studies have found that this drug is a rapid and effective treatment for symptoms of depression. In making this discovery, neuroscientist Lisa Monteggia and colleagues at the University of Texas Southwestern Medical Center in Dallas have identified a new biochemical pathway important in depression.
The anesthetic effects of ketamine work by blocking a receptor in the brain known as NMDAR. Monteggia and colleagues have determined that ketamine also stimulates brain production of a protein called brain-derived neurotrophic factor (BDNF). NMDAR receptors are activated for specific tasks such as learning, memorizing, or thinking and also serve as background noise.
Monteggia determined that production of BDNF turns off the background noise, which is believed to contribute to symptoms of depression. Ketamine increases BDNF production and thus may act in a manner similar to electroconvulsive therapy through resetting background noise associated with depression. Monteggia is enthusiastic that the link between background noise and depression offers a significant and new approach to the treatment of this problem.
Another very important aspect of this discovery is the speed with which ketamine seems to alter depressive symptoms. Common antidepressants such as Zoloft or Paxil require weeks to show improvement. However, research studies in mice show that ketamine exerts its affects in a few hours. Still, potential for ketamine abuse poses a problem in relation to long-term use of the medication. More research, including clinical trials, needs to be done to determine the safety and efficacy of ketamine in treating depression. However, identification of a new neurological pathway related to depression and understanding the actions of ketamine can assist nurses in providing care for a common and serious problem.
Source: Williams S. Why ketamine makes you happy. ScienceNOW. June 15, 2011. Available at http://news.sciencemag.org/sciencenow/2011/06/why-ketamine-makes-you-happy.html . Accessed on June 20, 2011.
Submitted by: Robin E. Pattillo, PhD, RN, CNL, News Editor at NENewsEditor@gmail.com.