The anesthetic ketamine hasn’t been approved to treat depression, but that isn’t stopping doctors from prescribing it for that very purpose.
“This is really an unusual situation in which a drug that was approved as an anesthetic is available to be prescribed by any physician,” explained Charles Nemeroff, M.D., Ph.D., a professor and chairman of the department of psychiatry and behavioral sciences at the University of Miami.
“And while we are used to prescribing things off label all the time — obviously, medications find other uses — to take a drug like ketamine, which is an anesthetic and a well-known drug of abuse, especially when there are no data on its long-term effectiveness or its safety, is very worrisome.”
The pros and cons of ketamine use for depression
Researchers first recognized ketamine as a potential treatment for depression when they discovered that N-methyl-D-aspartate (NMDA) receptor antagonists — or the same kind of drug as ketamine — relieved depressive-like symptoms in animals.
In 2006, the antidepressant attributes of NMDA receptor antagonists in humans were confirmed. A research team led by Carlos Zarate, M.D., at the National Institute of Mental Health found that a single IV dose of an NMDA antagonist produced profound relief of depressive symptoms in under two hours and remained significant over the course of a week. Considering that most antidepressants take several weeks before symptoms abate, this study was both encouraging and unprecedented.
Unfortunately, since these results, very few studies have focused on using ketamine as a treatment for depression. Last year, a group of researchers conducted a meta-analysis (or an intensive, quantitative review of the scientific literature) and found that only 12 studies examined the effects of ketamine on depression, either alone or in conjunction with other treatments.
Although the vast majority of studies in the meta-analysis supported ketamine’s efficacy, the researchers also found that the therapeutic effects dissipated quickly and that many of the patients experienced dissociative and psychotomimetic side effects. Two recent studies also revealed that recreational ketamine use is associated with bladder toxicity and may damage the bladder lining.
Researchers caution against off-label use of ketamine
The authors who performed the meta-analysis on ketamine cautioned clinicians against prescribing ketamine as a treatment for depression, at least in most circumstances. Since so few studies examine ketamine’s short-term efficacy — and virtually no studies have studied its safety in the long-term — it seems better to play it safe.
“The fleeting nature of ketamine’s therapeutic benefit, coupled with its potential for abuse and neurotoxicity, suggest that its use in the clinical setting warrants caution,” the authors concluded.
For individuals who are in a psychiatric crisis and cannot afford to wait several weeks for antidepressants to take effect, however, ketamine might be the ideal choice.
“First, current antidepressants, although quite effective for many people, still leave almost two-thirds of our patients in a situation where they do not have a complete response, and about one-quarter to one-third of patients gain little benefit,” explained Gerard Sanacora, M.D., Ph.D., a professor of psychiatry at Yale University, to Medscape Medical News.
“Secondly, even when these medications are effective, it can take up to several months before patients get complete benefit, and that’s a long time for a patient to be suffering.”
For this reason, clinicians like Sanacora are offering ketamine to their patients, but only after a careful evaluation to make sure the benefits outweigh the risks.
“So I think ketamine has the potential to really benefit some people, but we really do have to be cautious about the risks associated with its use,” said Sanacora. “Used in a controlled way, however, I think ketamine could have great clinical benefit.”
Patients at Sovereign Health of Florida’s mental health treatment program benefit from scientifically based modalities and effective group therapy sessions, in which each patient can receive the attention that he or she deserves. Prior to treatment, our patients receive a thorough assessment that can include psychiatric and medical evaluations to identify — and ultimately treat — any underlying medical conditions that may further influence their mental well-being. For more information on how we treat depression or other mental illnesses, please contact our 24/7 helpline.
About the author
Courtney Lopresti, M.S., is a senior staff writer for the Sovereign Health Group, where she uses her scientific background to write online blogs and articles for a general audience. At the University of Pittsburgh, where she earned her master’s in neuroscience, she used functional neuroimaging to study how the human cerebellum contributes to language processing. In her spare time, she writes fiction, reads Oliver Sacks and spends time with her two cats and bird. Courtney is currently located in Minneapolis. For more information and other inquiries about this article, contact the author at firstname.lastname@example.org.
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