Matthew Perry died from the "acute effects of ketamine," according to an autopsy report released by the Los Angeles County medical examiner more than a month after the Friends actor died.

The 54-year-old was found unresponsive after he drowned in his pool at his Los Angeles home on October 28, the examiner said on Friday.

His drowning, coronary artery disease and the effects of buprenorphine — a medication used to treat opioid use disorder — were noted as factors that contributed to his death, but were not the primary cause, according to the autopsy results. The death was ruled an accident.

Perry had a history of drug addiction, a struggle he detailed in his memoir published last year. The report noted his past drug use but adds that he was "reportedly clean for 19 months."

The report says he had been receiving ketamine infusion therapy for depression and anxiety, with his most recent infusion having occurred 1 1/2 weeks before his death.

But the ketamine that was in his system at the time of his death "could not be from that infusion therapy, since ketamine's half-life is 3-4 hours, or less," the examiner said.

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