The use of the drug ketamine has evolved since its development in the 1960s as a human and animal anesthetic. Today, it's known both as a promising new treatment for severe depression and as a psychedelic party drug.
It's also now tied to the tragic death of Friends star Matthew Perry.
The actor died from the acute effects of the mind-bending drug, ketamine, according to the actor's autopsy report. The 54-year-old accidentally drowned at his Los Angeles home.
Here's more information about ketamine.
Ketamine has been known to treat serious depression
In 2006, researches at the National Institutes of Health showed that an intravenous dose of ketamine could relieve severe depression in a matter of hours. That's compared to other remedies for depression, like Prozac and Zoloft, that often take weeks to ease the condition and don't work for every patient.
In 2018, Dr. Martin Teicher, an associate professor of psychiatry at Harvard Medical School and director of the Developmental Biopsychiatry Research Program at McLean Hospital told NPR that he considered the new uses of ketamine as "actually one of the biggest advances in psychiatry in a very long time."
And in 2019, the Food and Drug Administration approved Spravato, a nasal spray and the first antidepressant based on ketamine.
But even though ketamine works quickly, the effects wane after a few days or weeks, research has shown.
Perry himself was using ketamine infusion therapy for depression and anxiety, with the most recent infusion provided a week and a half before his death, his autopsy report said. But the ketamine used for that therapy was unlikely the cause of Perry's death as the half-life of the drug in the system is around three to four hours or less, the report said.
It's unclear still how or when Perry received more ketamine in the hours before he died.
Scientists have continued to study other ways to use ketamine to treat other psychiatric problems like substance use disorders and PTSD.
Researchers are also trying to extend ketamine's effects. A study published last year showed that the drug given to patients who play computer games designed to boost self-esteem after a ketamine infusion appeared to prolong the benefits of the anesthetic for up to three months after the therapy.
It's also been linked to another high profile death
Elijah McClain was killed after a stop by three police officers turned violent while he was walking home in Aurora, Colo. in August 2019.
The 23-year-old was brought to the ground by three officers and was given two carotid holds. Two Aurora Fire Rescue Paramedics called to the scene then administered a large dose of ketamine — at least 500 milligrams — to McClain. His heart stopped while in the ambulance and he never regained consciousness. He was pronounced brain dead a few days later.
The trial in several felony charges against the paramedics, Peter Cichuniec and Jeremy Cooper, is ongoing.
The trials for Aurora Police Officers Jason Rosenblatt and Nathan Woodyard ended in acquittals. The trial for the third officer, Randy Roedema, ended in lesser charges.
What are the risks with ketamine?
Ketamine has also been used at parties and clubs because of its ability to make a user feel like they are having an "out of body" experience and hallucinations for a short time.
Overdosing on the drug can result in a variety of symptoms including amnesia, or seizures, according to the American Addiction Centers. It can also cause someone to fall unconscious and or experience dangerously slowed breathing, according to the Drug Enforcement Administration.
But ketamine rarely causes an overdose if it's the only drug a person takes, according to the American Addiction Centers. Fatalities are more likely when ketamine is mixed with alcohol. It can also be associated with accidental injury or death in car crashes or drowning, as in Perry's case.