The 'Turning Tables' singer is said in the book, which will be released next month, to have developed a "drinking problem" at the beginning of her career after her bisexual boyfriend was unfaithful.
"I got so drunk by the time I went on [for a gig] at 2am I had forgotten the words to my own songs," she is quoted as saying by author Marc Shapiro.
Another passage from the book reads: "Adele would drink more than normal to salve the heartbreak... midway through her first tour, she allegedly had a drinking problem."
Speaking about the 21 star's biography recently, Shapiro insisted that the retelling of her life will be "without overt sensationalism" as she has "remained largely that salt-of-the-earth girl from Tottenham".
Adele claimed previously that she is at her most creative when drunk.
Watch Adele perform 'Set Fire to the Rain' below: