Rosie O’Donnell has said Michelle Trachtenberg was struggling with drug and alcohol addiction in the years leading up to her death at the age of 39 in February 2025.
Trachtenberg, best known for her work on Buffy the Vampire Slayer, was discovered dead in her apartment near Columbus Circle in New York City by her mother, according to police sources previously cited by ABC News.
In the weeks after her death, there was speculation that the actress had recently received a liver transplant and may have faced related complications. But the New York City Office of Chief Medical Examiner later determined that her official cause of death was complications from diabetes mellitus and ruled the death natural. The finding came after lab testing, following an initial undetermined ruling when her family declined an autopsy for religious reasons.
O’Donnell, 64, who appeared with Trachtenberg in the 1996 film Harriet the Spy, reflected on the loss in an interview with Variety published on July 17, 2026, and said the actress appeared to be in declining health during their last interactions.
“It was a tragedy,” O’Donnell said. “She was a real genius child who was able to memorize anything, pick up her lines, you could improvise with her, and she was connected and right there.
“She was so close to her mother, Lana, and her sister, who’s a ballerina.”
She also said Trachtenberg had become involved with drugs and alcohol before the two eventually lost contact. O’Donnell said they tried several times to meet again in the actress’s final years, but those plans never worked out.
“We were supposed to see each other three or four times, and she just never showed up, sometimes at restaurants, other times at my house where we’d had someone prepare the whole meal,” O’Donnell said.
“I would call her and go, ‘Honey, are you heading over?’ and she’d go, ‘Was that today?’ She was not in good shape.”
O’Donnell added that she had spoken with Trachtenberg’s mother in an effort to better understand the situation, and said she did not expect it to end in death.
“I didn’t think that she would die,” O’Donnell said. “With most people suffering from addiction, their loved ones think that they’ll survive it, but you can die from your addiction to drugs or alcohol, and it happens too often that it must be taken seriously.”
New York City’s Office of Chief Medical Examiner later said Trachtenberg died from complications of diabetes mellitus and ruled the death natural.
Authorities did not immediately say whether she had type 1 or type 2 diabetes. Her family had earlier cited religious grounds for not wanting her full autopsy findings made public.
Police told the Daily Mail they responded to a Manhattan apartment in Hell’s Kitchen in February, where Trachtenberg was found “unconscious and unresponsive.”
The actress was known for keeping details about her health largely private.
Trachtenberg began acting as a child and later became widely recognized for playing Dawn Summers opposite Sarah Michelle Gellar on Buffy the Vampire Slayer from 2000 to 2003, as well as Georgina Sparks opposite Blake Lively on Gossip Girl from 2007 to 2012.