New research has found that the veterinarian drug ketamine hydrochloride when used experimentally relieves symptoms of depression and suicidal tendencies within hours instead of the months it takes today’s antidepressants to work.
Chief Experimental Therapeutics of the Mood and Anxiety Disorders Program at the National Institute of Mental Health at Washington University, Carlos Zarate, has been studying how ketamine can be used in treating depression, anxiety and related disorders as current drugs prescribed like Prozac and Paxil, not only have many unpleasant side effect including nausea, headaches, insomnia and sexual performance, but take weeks to take effect and for many don’t work.
Ketamine, which has the street name of Green, K, super K, special K or Vitamin K, is traditionally used as a pain reliever or anaesthetic for humans but more commonly for pets. However in the 1970s recreational drug users found that it could give you a ‘high’ by changing a person’s thinking and perception of time and emotions.
The drugs currently used for depression work by regulating brain chemicals serotonin, norepinephrine and dopamine, which can effect emotion and feeling of wellbeing. This method works very slowly as it is hard to decipher what the chemical imbalance is. The problem could be the brain making too much of a particular chemical or they may be a problem with the brains receptors to the chemical, so sufferers of depression usually spend months to years trying to find the drug that suits them best.
However ketamine acts on a chemical called glutamate, which is much closer to the problem, Zarate says. Zarate has been working on ketamine since early 2000, when he began to hear anecdotal reports that ketamine could relieve depression almost instantly.
The war on depression is getting mighty weird these days. Last week, scientists said psilocybin, the active ingredient in ‘magic’ mushrooms, could be useful in treating depression. This week? Beat the blues with ketamine! The drug – also known as ‘Special K’- can lift even suicidal depression in just a few hours, researchers say.
Ketamine is approved by the FDA as an anesthetic. It’s mainly used as a horse tranquilizer, though it can be used to sedate both people and other animals. It’s also used by people recreationally, and is capable of producing hallucinations. I had friends who got really into its use in college (between this study and the mushrooms business, my college friends should have been the least depressed people ever …). Mostly, the high seemed to invoke a lot of sitting around in a silent, dazed stupor and occasionally falling into ‘K-holes.’ It didn’t look like much fun.
But ketamine could be really beneficial for treating major depression, according to some doctors. It works much quicker than typical antidepressants, which take weeks or months to really make a difference. And it could work for people whom typical antidepressants haven’t helped. Why? Carlos Zarate, a brain researcher at the National Institute of Mental Health who is studying ketamine, told NPR that depression is like a leaky faucet in the brain.
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That’s nice, but ketamine can come with side effects that make antidepressants look like aspirin. These include urinary tract problems, hypertension, nausea, nightmares, memory problems and hallucinations. Zarate said because of troubling side effects, ketamine is unlikely to become a common depression treatment in and of itself. But understanding how ketamine works at treating depression could allow scientists to develop safer drugs that work in the same way.
A few of these drugs – scopolamine, which is used to prevent seasickness; a pill called riluzole – are already being tested on depression patients. Both of these drugs also affect the glutamate system, though researchers aren’t quite sure how. But one patient who took part in an NIH trial of scopolamine said:
“There’s no doubt in my mind [that] however it works or whatever receptors in the brain it works on, absolutely it has nailed exactly where my imbalance is.”
While it’s unlikely you’ll be filling a Special K or ‘shroom prescription any time soon (darn!), it’s pretty cool that researchers are using studies of these drugs to find new, safer and more effective ways to treat depression.
“We can take care of a migraine in hours,” says Zarate, “So why do we have to wait weeks or months with depression?”
The study included 17 volunteers with depression who had not responded to previous drugs. Researchers found that after a single dose of ketamine, 12 of the 17 got much better within hours. And the effect lasted for more than a week.
Researchers from Yale had previously found that the glutamate system can affect brain cells when forming new connections, and that stress and long term depression could weaken some of these connections. However ketamine appears to reverse the process.
Ketamine blocks a chemical called glutamate in the brain, which is different from the action of many antidepressants. Most antidepressants work on the neurotransmitters, of which serotonin is the most well known. Ketamine can help put a patient to sleep for surgery or relieve a patient who is in pain by placing them in a kind of trance called ‘dissociative anesthesia’. For this reason, the drug can also be abused, helping those who wish to leave reality; the drug can also cause hallucinations similar to PCP.
Small studies of 6-33 patients receiving low-dose ketamine have shown impressive results in reducing depression and suicidal thinking. One study showed improvements in depression within 40 minutes! Others showed improvement within hours to days, which is much shorter than the weeks to months traditional antidepressants or psychotherapy can take to have an effect. The effect lasted 7-10 days in some trials.
Although ketamine itself will not be administered as an antidepressant as it has many side effects including hallucinations and is extremely addictive, it could be key to discovering how to make faster acting drugs for depression.
The Australian government Department of Health and Aging claim about 20 percent of Australians will be affected by depression and 6 percent will experience a major depressive illness and the greatest numbers of people with a mental illness are in the 18-24 year age group.
Today’s antidepressant medications eventually end up doing the same thing, but they go about it the long way around, with a lot of biochemical steps that take time. Now we’ve shown what the key targets are and that we can get at them rapidly,” said Zarate. “Ketamine probably can’t become the medication of choice, but this research is leading to some very real possibilities for a whole new generation of antidepressant medications.”
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