05/08/2010 AT 9:45 AM ET
Alexa Ray Joel is famous for three reasons: her music, her parents (Billy Joel and Christie Brinkley), and regretfully, a battle with depression that landed her in the hospital after an overdose on Dec. 5.
“I felt like I was in a black hole and I couldn’t see out,” Joel, 24, reveals in the new issue of PEOPLE. “I hit rock bottom that day … A part of me wanted people close to me to know – not the whole world.”
The trigger for her depression? A very bad case of heartbreak. Joel says she never really got over her first love, her former bassist Jimmy Riot, whom she began dating at 19. They broke up in 2008, but had fleeting reconciliations. “I was addicted to this man,” she says, “and it spiraled out of control.”
Joel now sees a therapist regularly and is talking more openly to her parents. But tabloid reports that her overdose stemmed from a fight with Brinkley over her weight still upset her.
“It had everything to do with my depression, my anxiety, a dysfunctional on-and-off relationship with my ex – nothing to do with my relationship with either one of my parents,” she says.