The autopsy found that Perry had been receiving ketamine infusion therapy for depression and anxiety but the ketamine detected in his system at death could not have been from his last therapy session, which conducted about a week and a half before he died.
This is because ketamine’s half-life, or the time it takes for the amount of the drug to be reduced in the body by 50 per cent, is about three to four hours.
In his memoir Friends, Lovers, and the Big Terrible Thing, Perry wrote about receiving ketamine infusions at a rehab center in Switzerland during the pandemic, explaining that a synthetic form of the dissociative anesthetic is used “to ease pain and help with depression.”