AceShowbiz - Soap star Billy Miller died from a self-inflicted gunshot wound. The "General Hospital" actor's cause of death has been revealed after he was found dead on September 15 aged 43 at his home in Austin, Texas, days before he was due to turn 44, following a long battle with bipolar disorder and manic depression.

An autopsy reported obtained by RadarOnline.com has shown the actor was found in his bathtub "with an apparent gunshot wound to the head." First responders were said by the document to have found "multiple letters indicating suicidal intent" and "a revolver chambered for .410 shotgun shells" in "the descendant's right hand."

Billy, who wasn't married and had no children, also had several drugs and alcohol in his system at the time of his death, including "cocaine, and its metabolites, diphenhydramine, and amphetamine." His blood alcohol level was listed at 0.08, according to Radar.

Billy's mum Patricia revealed a few days after the shock death of her "The Young and the Restless" star son he had "surrendered his life." She told Soap Opera Digest, "He fought a long, hard, valiant battle with bipolar depression for years. He did everything he could to control the disease."

"He loved his family, his friends and his fans, but in the end, the disease won the fight. We all loved him so much and are desperately trying to deal with our loss," she added, before concluding, "I will have nothing further to say. Thanks for the love and support."

Billy got his big break in 2007 when he landed his first big TV role as Richie Novak on "All my Children". He was cast as Billy Abbott on "The Young and the Restless" a year later, and starred on the CBS series from 2008 to 2014.

His performance earned him three Daytime Emmy Awards, two for best for outstanding supporting actor in a drama series and one for outstanding lead actor in a drama series. He went on to play Drew Cain and Jason Morgan on "General Hospital", on which he was a series regular until 2019.