A singer and actress who rose to fame as a star on the Disney Channel was hospitalized after what is believed to be a heroin overdose. TMZ reports that paramedics responded to the home of Demi Lovato, where they found Lovato unconscious.

“Law enforcement sources tell us Demi was treated with Narcan — an emergency treatment for narcotic overdoses — at her home. We’ve confirmed the OD occurred at her house in the Hollywood Hills,” TMZ reports.

The report adds: “Demi was out Monday night celebrating a friend’s birthday in West Hollywood, and we’re told she posted photos on her private Instagram of herself and others in the group. She seemed happy in the pics.”

Lovato, who has waged a high-profile battle with substance abuse, was reportedly taken by ambulance just before noon today to an area hospital.

Lovato, 25, discussed her past drug use in a YouTube documentary released last fall, called “Simply Complicated.”

The Hollywood Reporter quotes her saying in the documentary: “I felt out of control the first time I did it. My dad was an addict and an alcoholic. Guess I always searched for what he found in drugs and alcohol because it fulfilled him and he chose that over a family.”

THR adds: “YouTube announced in May that it has plans for another show with Lovato in which she ‘pays it forward’ to some of her fans.”

Lovato, who broke out with roles on the Disney Channel shows “Camp Rock” and “Camp Rock 2: The Final Jam,” released a song last month called “Sober,” in which she revealed that she had relapsed in her battle with substance abuse.