Ketamine, an anesthetic used by veterinarians and whose consumption is spreading like a recreational drug, may hide the key to a new generation of antidepressants. Over the past decade, scientist have been investigating its properties, it is always injected in small doses under medical supervision, to combat sadness. The most surprising is that it acts much faster than standard treatments, and has now been discovered the brain mechanism that generates this fast response. “A dosage acts quickly and lasts seven to 10 days,” says Professor of Psychiatry and Pharmacology, Yale University (USA) Ronald Duman, whose study on rats has revealed that ketamine activates a brain protein called mTOR.
This process did not occur in other antidepressant treatments, such as fluoxetine (Prozac) and imipramine (Tofranil), so scientists have determined that it is the key to the immediate effect of the substance. After being treated with mild doses of ketamine, rats developed new neural connections, or synapses, in the cells of the frontal lobe that had been damaged after prolonged exposure to stressful situations. But the main advantage of ketamine over other antidepressants is acting fast, which is important because current treatments can take weeks or even months to work fully. Only one in three depressed patients respond favorably to the first drug they are administered, so it may take months or even years trying different options. And in some cases, no drug appears to work.
Ketamine, however, has achieved in previous studies that 70% of refractory patients within hours improved. Duman and colleagues, whose results were published in the journal ‘Science’, hope their description of the process that triggers this response allows new drugs that act quickly. So far, clinical use of ketamine as antidepressant experimental studies is limited because it may cause psychotic reactions. Moreover, the application for this use is complicated: it must be given intravenously and under medical supervision. For recreational use, the consequences are potentially severe and uncontrollable.