'Go Ask Alice' Debunked at Snopes.com
Snopes debunked "Go Ask Alice" ages ago:
http://www.snopes.com/language/literary/askalice.asp
Quotes:
Go Ask Alice was the product of Beatrice Sparks, an author who has come out with a number of "teens who saw their lives ruined by their bad choices" offerings, each one presented as a true story, often in the form of a diary of an anonymous teen
The precise authorship of Go Ask Alice is still a bit of a mystery. Beatrice Sparks is presented as its editor rather than its author, and one tantalizing mention in a 1998 New York Times book review indicates the book might have been the work of several people:
Linda Glovach, since exposed as one of the "preparers" — let's call them forgers — of Go Ask Alice, has just written Beauty Queen, about a girl who flees her alcoholic mother, becomes a stripper and dies of heroin addiction.
Our best guess is that a number of folks work at churning out these cautionary tales, which are then presented to an overly accepting public as real diaries of anonymous teens. Yet on the question of authorship, one thing is startlingly clear: whoever wrote the Go Ask Alice "diary" was not a 15-year-old girl.