Adele has overcome her fair share of obstacles over the last several years, including relationship struggles and a serious vocal cord complication. Now, a new (unofficial) biography on the Grammy Award-winning artist's life is shedding light on her alleged battle with alcohol abuse.

Mark Shapiro, the author behind 'Adele: The Biography,' revealed in a recent interview that her supposed drinking problem can be traced back to her alcoholic father, whom she felt very alienated from. She then fell headfirst into an unstable romantic relationship that only worsened her dependency on alcohol. According to Shapiro, "Adele would drink more than normal to salve the heartbreak."

Shapiro's book says that her struggles with alcohol impacted not only her private life, but her singing career as well. At a concert during a particularly dark time, Adele confessed to being so drunk that she'd "forgotten the words to my own songs … It was the worst thing ever."

This isn’t the first time she has come forward about this issue. Back in 2009, she told Spinner that she gave up drinking for a while, but the habit unfortunately came back to haunt her: "My voice would never be in form because I'd be hungover … It was just affecting my professionalism."

These days, Adele is trying to live a much healthier lifestyle that focuses on the positive instead of dwelling on the troubles of her past. The biography is scheduled to come out on July 17 through St. Martin’s Press.