Cathriona White, Jim Carrey's on-again, off-again girlfriend, was found dead of an apparent suicide Monday night (September 28), according to TMZ. She was 28.

The site says Los Angeles police responded to a call and found White's body beside a suicide note written to Carrey that referenced the couple's September 24 breakup. White and Carrey had been seeing each other on and off since 2012.

Police told TMZ they believe the suicide was the result of an overdose, and discovered pills around White's body in her Sherman Oaks home, according to Ireland's Independent. TMZ says two of White's friends first found her motionless after going to check on her.

On September 24, White tweeted "Signing off Twitter, I hope I have been a light to my nearest and dearest."

The Independent noted that White, an Irish native, was training to be a beauty therapist before moving to Los Angeles in 2009 to seek a career as an actor. She had most recently been working behind the scenes, the site says.

In 2013, Carrey confirmed to the Independent that he'd been seeing an Irish girl, and called her "lovely."

According to US Weekly, Carrey and White had gotten back together as recently as May, and a source told the magazine "They're having a great time now."

On September 16, Carrey tweeted a photo that White had taken in Grand Central Station in New York City. The image finds him dressed in a white jacket and matching shirt in a nearly empty terminal, and the caption reads "I am nothing. What a relief."

See the last things these celebrities tweeted before their deaths: