A psychedelic renaissance is underway in medical research as certain taboo drugs return to the hands of doctors and researchers after decades in the wilderness. Once considered illicit, with no medical value, these psychedelic compounds are now being legitimately evaluated by scientists and revolutionizing how we practice medicine.

Psychedelic medicine 101 is a series that will investigate the past, present and future medical uses of these formerly taboo substances. Our first feature examined the story of psilocybin and magic mushrooms, while this new episode documents the curious story of ketamine, initially developed to be an anesthetic before researchers and psychonauts discovered its unique and unusual effects on the brain.

The curious case of ketamine

In 1956, a chemist at pharmaceutical company Parke Davis in Detroit, Michigan was experimenting with synthesizing new compounds in an attempt to find a better anesthetic. A compound called phencyclidine was initially created, and in early animal studies it demonstrated defiantly unusual effects. Some animals exhibited a drunk-like state when administered with it, while others entered states of delirium.

Human tests quickly ruled out the compound as clinically useful with some patients exhibiting major delirious and dissociative states for prolonged periods of time. This was despite the fact the it did seem to function remarkably well as an anesthetic. In later years, phencyclidine hit the streets as a recreational drug, becoming infamous due it its violent side effects. Its street name was PCP, or angel dust.

In the early 1960s, Parke Davis researchers began searching for a phencyclidine derivative that could limit the compounds unmanageable side effects. It was here that ketamine was born and after successful animal tests it was administered to the first human subject in 1964, demonstrating remarkable anesthetic effects.

Initially approved for veterinary uses, ketamine quickly found a place as an effective short-acting anesthetic, officially passed by the FDA in 1970 for human uses. One of its first major human uses was as a battlefield anesthetic in Vietnam. It has been suggested that this initial use in the early 1970s was what led to it moving into recreational circles as veterans returned to the United States and continued using the drug.

Non-medical uses continued throughout the 1970s, culminating in several high profile publications "outing" the drug. Perhaps the most infamous of these accounts came in scientist and psychonaut John C. Lilly's 1978 autobiography The Scientist: A Novel Autobiography.

Ketamine, sensory deprivation and alien communication

John C. Lilly is perhaps best known for his work blending LSD, isolation tanks and human-animal communications. After developing the first isolation tank in 1954, Lilly began experimenting with LSD in the tanks in the early 1960s. His extreme work sat at the boundary of conventional science, and the extraordinary 1980 psychedelic film Altered States was significantly inspired by his experiences.

It was the early 1970s, however, when Lilly first crossed paths with ketamine. Lilly had long suffered extreme migraines, almost daily, for much of his life. During an attack, a physician friend suggested ketamine may be helpful. So Lilly jumped into an isolation tank, was injected with a small dose of ketamine, and his migraine disappeared … for 20 minutes. When it roared back his physician friend gave him another injection, this time double the dose. For about half an hour the migraine disappeared, but then it stormed back, so finally the physician again doubled the dose and sent Lilly back into the tank.

After an hour Lilly got out of the tank and his migraine had gone. A month later, with his migraine still yet to return, Lilly became convinced ketamine had somehow reprogrammed his brain in ways that his earlier massive LSD experiences couldn't. For the next few years Lilly's personal ketamine experiments became more and more extreme.

Lilly became convinced he could communicate with a network of extraterrestrial entities he dubbed ECCO, or the Earth Coincidence Control Office. ECCO guided Lilly's research but as he began to consume more and more ketamine he came across another, more malevolent entity called SSI, Solid State Intelligence.

SSI was a massive cosmic supercomputer, with evil intent. At one point, in the midst of an epic nearly month-long physical experiment with ketamine, consisting of injections nearly every hour, Lilly tried to contact President Gerald Ford to warn the world of a potential doomsday scenario. One of the president's aides intervened before Lilly could reach Ford.

These stories, and others, recounted in the late 1970s, slowly added to the infamy surrounding ketamine, but they also started to pique the attention of the authorities. The peripheral clinical uses of the substance were still pervasive enough for it to not be completely regulated until the United States government moved to make it a Schedule III controlled drug in 1999. This added a degree of regulatory oversight as to how the drug was dispensed but still allowed it to be utilized for clinical purposes.

The rise of the ketamine clinic

Unlike other more restricted drugs, ketamine is still available for medical uses. This has led to the recent upsurge of ketamine clinics in the United States. Ketamine is legally approved for use as an anesthetic, but its off-label use for other conditions is not illegal.

Since around 2015, it is estimated that well over 100 ketamine clinics have opened up in the US. These clinics target patients looking for an alternate way to treat their depression. For up to US$1,000 a dose, patients can receive an infusion of ketamine either weekly or monthly. Different clinics have different treatment processes, from specific 10-week programs to more casual dose-by-dose appointments.

It's the wild west of medical treatments out there, with no clear science on how long these treatments last, or how safe long-term ketamine use like this actually is. The CEO of Actify Neurotherapies, a chain of 10 treatment centers, said recently "It scares the hell out of me that this is still unregulated."

Actify Neurotherapies is actively resisting the term "ketamine clinic," recently rebranding itself as a mental health clinic that happens to also provide off-label ketamine treatments. While Actify is positioning itself at the more credible end of the off-label ketamine provider spectrum, it is still part of a troubling, unregulated industry with the science yet to offer real clarity on the best way this drug should be delivered.

A little less psychedelic?

The giant hurdle facing most ketamine research is trying to find a way to overcome the often unpleasant dissociative psychedelic effects of the drug. While NMDA-receptor antagonism is looking like an exciting new pathway to treat a whole host of conditions, the side effects of ketamine are proving tricky to manage when implemented into broader clinical applications.

A recent Australian trial into a ketamine nasal spray for treating depression had to be aborted after several participants started to experience psychotic-like side effects. One of the researchers suggested the dose problems stemmed from inconsistencies in the nasal-delivery method.

"We saw a range of tolerance levels and we think it's because one person's blood vessels in the nose can be so different to the next person's, and when you spray, it crosses the thin lining, gets taken into the blood and straight to the brain. Some people got huge hits."

Several researchers are now racing to develop compounds chemically similar to ketamine that still act on NMDA receptors but can reduce the psychoactive side effects. One of the most promising new alternatives is called esketamine, and it is currently at the tail end of Phase III clinical trials.

Esketamine is an isomer of ketamine, and reportedly has slightly less dissociative characteristics compared to its sibling. It is thought to be twice as potent as ketamine, which means it is suggested that lower doses could have similar NMDA-inhibiting effects to ketamine without the equivalent hallucinogenic result.

Ketamine + therapy = success?

Of course, some researchers are finding ways to work with the compound's extremely hallucinogenic properties. An exciting new trial currently underway at the University of Exeter and University College London is directly inspired by Evgeny Krupitsky's 1980s research in Russia. The trial is called KARE - Ketamine for reduction of Alcoholic Relapse, and it is setting out to examine how well ketamine, in conjunction with psychotherapy, can reduce alcohol dependence and promote abstinence.