'Young and the Restless' Star Kristoff St. John Official Cause of Death Revealed to Be Alcohol Abuse

The official cause of death for Kristoff St. John was released Tuesday. The Los Angeles County Medical Examiner said that The Young and the Restless star died accidentally from hypertrophic heart disease by way of alcohol abuse.

Investigators noted St. John's heart muscle had "myocardial bridging" and showed signs of alcohol abuse. The death was officially categorized as an accident, according to The Blast.

As previously reported, the soap opera star died last month at his home after police responded to possible alcohol poisoning. A cause of death was deferred until officials could get toxicology results. He was 52.

St. John was buried earlier this month at the Valley Oaks Memorial Park in Westlake Village, California beside his late son, Julian, who died by suicide in 2014.

Those in attendance to lay St. John to rest included many of his co-stars, including Melody Thomas Scott, Hunter King and Jason Thompson, as well as his beloved Shiba Inu, Brando. Not in attendance for the service was St. John's fiancée, Kseniya Mikhaleva, whose request for an emergency visa was denied. Mikhaleva, who became engaged to St. John in September of 2018, is a Russian native and currently lives in Moscow.

The actor's final episode of The Young and the Restless aired on Feb. 6, with a special tribute paid to him two days later. The CBS soap opera is also reportedly developing a storyline for April to honor the late actor.

St. John's death came less than five years after his son died by suicide in November 2014 following a lifelong battle with mental illness. In the years that followed Julian's death, St. John reportedly battled severe depression and was placed on a 72-hour psychiatric hold in October 2017 after threatening to shoot himself.

Along with his ex-wife, Mia St. John, he founded El Saber es Poder (Knowledge is Power) Foundation to combat mental illness.

Mia, a professional boxer, revealed earlier this month that she relapsed after 30 years of sobriety following Kristoff's death.

"I lost my 30 years' sobriety," Mia, 51, told PEOPLE. "I'm ashamed, believe me. I had 30 years of sobriety, I thought I was the s—. Like I was queen of mental health. I'm a mental health advocate. I felt as small as you can get. My ego was crushed. But I feel like I want to look at the bigger picture and my higher self."

"It's about the good of all. And if I can help someone out, and say if there's just nothing it doesn't mean that I'm a weak person. I'm just an imperfect person and we all have to find a way to pick ourselves up and carry on," she said.