Jeff wants to smile again and know what happiness is like again. He wants to not feel the urge to kill himself again. He has been hospitalized in psychiatric facilities and has taken a variety of antidepressants and mood stabilizers for his bipolar disorder, but nothing worked. He remained employed as a football analyst until the sky fell in on him and he lost his job. “He was suicidal; so overwhelmed with despair, that he couldn’t even leave his house.” He finally found a treatment option at the Ketamine Clinics of Los Angeles. And so goes one of many testimonies of ketamine’s potential as a rapid treatment for depression.

Steven Mandel MD, the President and founder of the Ketamine Clinics of Los Angeles, is an anesthesiologist who uses ketamine to treat patients who are depressed and suicidal. The standard protocol is to give low dose IV infusions of ketamine. It worked for Jeff. He said, “It’s been remarkable.” His wife looked at him and saw the smile on his face and had the biggest smile herself in response. Jeff thought it was immoral to withhold ketamine from the general public. You can watch a four-minute video on Jeff and Dr. Mandel’s treatment here.

Over the last ten to fifteen years, ketamine has been getting a significant amount of research and media attention as a fast-acting treatment for depression. Reporting for The Washington Post, Sara Solovitch quoted Dennis Hartman as saying: “My life will always be divided into the time before that first infusion and the time after.” But the relief is temporary. “Clinical trials at NIMH have found that relapse usually occurs about a week after a single infusion.”  And it can cause intense hallucinations or a kind of lucid dreaming or dissociative state where some patients lose track of time.

NIMH studies suggest the psychedelic experience with ketamine may play a small but significant role in the drug’s efficacy. Steven Levine, a psychiatrist who has treated 500 patients with ketamine said:

With depression, people often feel very isolated and disconnected. Ketamine seems to leave something indelible behind. People use remarkably similar language to describe their experience: “a sense of connection to other people,” “a greater sense of connection to the universe.”

Hartman travels back-and-forth to an anesthesiologist in New York City for his bimonthly infusions of ketamine. He doesn’t consider himself permanently cured, “but now it’s something I can manage.” In 2012 he helped to found an organization called the Ketamine Advocacy Network, a group that screens ketamine clinics, advocates for insurance coverage and spreads the word on the effectiveness of ketamine to treat depression. The problem is the treatment is not FDA approved. And in higher doses, ketamine is known as the club drug, “Special K.” See previous articles, “Ketamine to the Rescue?” and “Falling Down the K-Hole.”

The promise of ketamine as a fast-acting alternative to other antidepressant medications had led to a growth industry for ketamine clinics around the U.S. and multiple pharmaceutical companies doing their own research into developing ketamine derivatives without the side effects. Ketamine is known to interact with the NMDA receptor involved in learning and memory. So scientists assumed the same receptor was responsible for the anti-depressive action of ketamine. STAT News reported this led to more than a dozen companies trying to develop drugs that target the NMDA receptor. “But these drugs haven’t worked as well as ketamine.” AstraZeneca pulled out of developing its own highly touted ketamine derivative, lanicemine in 2013 when it failed to show long-term benefits.

Iadarola et al. published a 2015 article in the journal Therapeutic Advances in Chronic Diseases that reviewed the growing literature on ketamine efficacy as an antidepressant treatment. They confirmed the temporary effects from ketamine; the effects waned after several days in most patients. The authors suggested that after achieving the antidepressant response from ketamine, the effects could be maintained with intermittent doses of ketamine as described above with Dennis Hartman. Pharmaceutical companies aren’t really interested in moving forward with ketamine infusion since the drug has been long off patent and they can’t make a billion dollar profit on a drug that is off patent. So they seek to develop biosimilars to ketamine.

The latest pharma compound to target the NMDA receptor is esketamine, which Janssen Pharmaceuticals, a division of Johnson & Johnson, is developing as an intranasal spray. Johnson & Johnson announced on August 16, 2016 that the FDA granted esketamine a Breakthrough Therapy Designation. This is the second time esketamine has received a Breakthrough Therapy Designation. The first was in November of 2013. The Breakthrough Therapy Designation is to expedite drug development when a drug demonstrates the potential to be a substantial improvement over available therapies for serious or life-threatening conditions.

But the real excitement may still be ahead. The STAT article cited above reported on a new research study published in the May 26^th 2016 issue of the journal Nature that demonstrated a derivative of ketamine could achieve the same benefit, but without the side effects. The study was done on mice, so it has a ways to go in drug development before it can compete with esketamine. Dr. Todd Gould, who led the Nature study, suggested the ineffectiveness of previous studies that targeted the NMDA receptor were because they were looking in the wrong place. His research team showed that the effectiveness of ketamine as an antidepressant doesn’t come from the NMDA receptors—at least not in mice.

In the body, ketamine turns into a molecule called hydroxynorketamine — or HNK — and that molecule is actually what treats the depression. Gould’s team also found that HNK does not interact with the NMDA receptor, and it doesn’t have some of the side effects that ketamine does.

Gould said they have a game plan to move forward with the clinical development of HNK. He and his coauthors have filed a patent application for certain uses of HNK. Outside researchers thought the study was well-done science, but they aren’t convinced it’s time to give up on the NMDA receptor. Their drugs targeting the NMDA receptor are further along in drug development. And they are not convinced they are beating a dead horse just yet. STAT reported that Dr. John Krystal, a psychiatrist and neuroscientist who consults for companies developing NMDA-target drugs said: “In my view, it is quite premature to move away from the hypothesis that NMDA receptor antagonists have antidepressant activity based on this single study.” True, but to you rush to bring your ketamine-like drug to market first?

There will still be the same adverse effects as with ketamine, won’t there? And the temporary nature of the mood elevation is still there, isn’t it? The lack of long-term effects led to the AstraZeneca decision to stop development with lanicemine. And esketamine is “an investigational antidepressant medication, for the indication of major depressive disorder with imminent risk for suicide.” That sounds like a short-term use designation.

Uli Hacksell, chief executive of Cerecor, a Baltimore company that has a Phase 2 drug candidate directed at the NMDA pathway, also took issue with the claim that such drugs might be going after the wrong target, and he said that the paper will have no implications for his company’s development plans. “We think that the clinical data we get with our molecule will speak for themselves,” he said.

One outside researcher, Dr. Francis Collins, the director of the National Institutes of Health (NIH), was quite supportive of Gould’s research. In his NIH Director’s blog, Collins described the background work leading up to the Gould study. He then said:

 HNK appears to come without the side effects of ketamine. After receiving HNK, mice didn’t show changes in their physical activity, coordination, or sensory perception, as is normally seen after a dose of ketamine. HNK also doesn’t appear to have the same potential for abuse either. When given the option, mice will choose to self-administer ketamine, but not HNK.

The new evidence confirms that HNK doesn’t block NMDA receptors like ketamine does. While there’s more to discover about how HNK works, the evidence reveals an important role for AMPA receptors, another type of glutamate receptor in the brain.

Long-term ketamine users can have irreversible urinary tract and bladder problems. Erowid, a pro-drug website, conducted an online survey that indicated there was a clear correlation between total lifetime use of ketamine and the likelihood of reporting bladder/urinary problems. Now these are health problems that occur with higher doses of ketamine than those used to treat depression. Lower doses over the long-term may not have the same adverse effects. However, these known health concerns should not be overlooked in the rush to bring a new fast-acting antidepressant to market. Ketamine (and its derivatives) to the rescue of depression may not turn out to be the super cure some think it is.