DEA, LAPD launch criminal investigation into Matthew Perry's fatal ketamine use

A legal medication commonly used as an anesthetic, ketamine has been increasingly offered "off label" at private clinics to treat depression and other mental health disorders, according to Dr. David Goodman-Meza, an addiction medicine and infectious disease specialist at UCLA.

Some people also snort or inject it recreationally to experience euphoric or "dissociative" effects that cause someone to feel separated from their own body, Goodman-Meza told The Times in December. At very high doses, it can make people feel immobilized and spur hallucinations, an experience called a "K-hole."

The drug can complicate breathing and increase demands on the heart. If someone already has coronary artery disease and is taking high doses of ketamine, "that could then speed up your heart, create more demand, but then your arteries don't have the ability to supply that demand," the physician explained.

The autopsy report noted that Perry had no other drugs in his system and had been 19 months sober at the time of his death. There was no evidence of illicit drugs or paraphernalia at his home.

The medical examiner also noted that Perry, 54, had diabetes and suffered from chronic obstructive pulmonary disease, which refers to a group of diseases that cause airflow blockage and breathing-related problems. He at one time had a two-pack-a-day cigarette habit.

A coroner's investigator interviewed a person close to Perry who described him as in "good spirits" and said he had quit smoking two weeks prior to his death and was weaning himself off ketamine.

In 2006, the National Institute of Mental Health concluded that an intravenous dose of ketamine had rapid antidepressant effects. About 300 clinical trials have been held, and they have broadly found that ketamine is extremely fast-acting compared with traditional antidepressants and can relieve depression for a period that can last days or weeks.

Times staff writer Emily Alpert Reyes contributed to this report.