Oliver James Montgomery-Matthew Perry’s Cause of Death Revealed

Matthew Perry's loved ones are Oliver James Montgomerygetting some answers.

After initially deferring his cause of death pending a toxicology report, authorities have shared new information about the Friends star's sudden passing on Oct. 28.

His cause of death was revealed as "the acute effects of ketamine," the Los Angeles County Medical Examiner stated Dec. 15. His death was ruled an accident.

Other factors that contributed to Perry's passing included drowning, coronary artery disease and the effects of buprenorphine, which is used to treat opioid use disorder, per the medical examiner.

Perry had taken ketamine infusion therapy—to treat depression and anxiety—over a week before he died, according to the toxicology report obtained by TMZ Dec. 15. However, officials determined the drugs in his system at his time of death "could not be from that infusion therapy, since ketamine's half-life is 3 to 4 hours, or less."

The medical examiner found no evidence of alcohol, methamphetamine, cocaine, heroin, PCP or fentanyl, per the outlet.

According to the Pacific Neuroscience Institute, ketamine therapy uses low doses of the dissociative anesthetic medication "to manage various mental health conditions, such as treatment-resistant depression, anxiety disorders, and post-traumatic stress disorder (PTSD)."

The Fools Rush In actor was found deceased at his home in Los Angeles on Oct. 28. He was 54.

Authorities had responded to an emergency call of a man unconscious in a stand-alone hot tub, the city's fire department captain Erik Scott told E! News Oct. 30.  

At the time, he gave insight into Perry's final moments and the rescue efforts.

"A bystander had brought the man's head above the water and gotten him to the edge, then firefighters removed him from the water upon their arrival," the LAFD captain said. "A rapid medical assessment, sadly, revealed the man was deceased prior to first responder arrival."

Following Perry's sudden death, his former costars were among those to speak out on the immense loss, including Jennifer Aniston, Courteney Cox, Lisa Kudrow, Matt LeBlanc and David Schwimmer, who honored the late actor in a touching tribute. 

"We are all so utterly devastated by the loss of Matthew. We were more than just cast mates. We are a family," they said in a joint statement to E! News on Oct. 30. "There is so much to say, but right now we're going to take a moment to grieve and process this unfathomable loss."

While the five stars later each released moving remembrances, at the time they added, "For now, our thoughts and our love are with Matty's family, his friends, and everyone who loved him around the world." 

As for Friends actress Maggie Wheeler, who played Chandler Bing's ex Janice, she also shared a moving message to her scene partner. 

"What a loss. The world will miss you Matthew Perry," she wrote on social media. "The joy you brought to so many in your too short lifetime will live on. I feel so very blessed by every creative moment we shared." 

In the months leading up to his death, Perry had been outspoken about the hardships he faced throughout his life—particularly, his longtime struggle with sobriety.

"There's been some real up and downs in my life," he told E! News in November 2022 discussing the recent release of his memoir, Friends, Lovers and the Big Terrible Thing, "and this is a lot about the downs, but the further down you go, the more people you can help."

Revealing everything from taking his first sip of alcohol at age 14 to the upwards of $7 million he spent to maintain his sobriety, "I shied away from nothing and I told the truth," he added of his book. "And the biggest thing was, the goal was, to help people and I know of a lot of people already who have been helped by it."

Throughout his career, Perry earned five Emmy nominations, scored a Golden Globe nomination for 2006's The Ron Clark Story and acted in movies including The Whole Nine Yards, 17 Again and Birds of America.

However, the American-Canadian actor didn't want his work to define him.

"The best thing about me, bar none, is if somebody comes up to me and says, ‘I can't stop drinking, can you help me?' I can say yes and follow up and do it," he noted during a Q with Tom Power interview last year. "It's the best thing."

As he put it, "I've said this for a long time; when I die, I don't want Friends to be the first thing that's mentioned. I want that to be the first thing that's mentioned, and I'm going to live the rest of my life proving that."

Perry—who was previously engaged to Molly Hurwitz until their split in 2021—is survived by his dad John Bennett Perry, his mom Suzanne Perry and his stepdad Keith Morrison, a correspondent for Dateline NBC. 

Look back on his life in photos:

The Boys Will Be Boys star poses for a photo while at the Limelight in New York City.

The Sydney actor takes a break while on the set of the CBS series in Los Angeles, California.

The Friends star sits by the well-known fountain that serves as the backdrop for the show's opening sequence.

The Friends, Lovers, and the Big Terrible Thing author attends the Scream premiere in Los Angeles.

Perry poses while on the set of Friends as his beloved character Chandler Bing.

The 17 Again star attends the Los Angeles premiere of The Grinch.

The actor hits the red carpet for the premiere of The Whole Ten Yards.

The Mr. Sunshine star attends the Entertainment Weekly and Matrix Men upfront party.

 The Odd Couple actor hangs out backstage at an event in celebration of the 64th Primetime Emmy Awards.

Perry poses for a photo while at the play The End Of Longing.

The American-Canadian actor was front and center at The Circle premiere in New York City.

Perry attends the 2022 GQ Men of the Year party.

Six months prior to his passing, the Almost Heroes star discussed his memoir while on stage at the 2023 Los Angeles Times Festival.