The 'Heart Attack' hitmaker, who sought treatment for "physical and emotional issues" in October 2010, is releasing a book 'Staying Strong 365 Days of the Year', a collection of quotes and goals she hopes will help other young people to find happiness.
The 21-year-old 'X Factor' USA judge wrote about the 'Serenity Prayer' in her book and said: "I have spoken about this prayer almost every day of my recovery.
"And it has helped me simplify the sea of emotions and feelings that often run through me, especially on a hard day.
"We can do the best we can in life, we take things one day at a time and sometimes we all just need a simple reminder of that."
The 'Serenity Prayer' chapter corresponds with the date March 15, which Demi says will always be important to her.
She explained on her Facebook page: "It's the anniversary of the day I began my recovery.
"As I share a part of my life with you, I want to hear your stories too. Comment below using #StayingStrong365 and tell me what helps you get through the hard days."
During an interview with 'Good Morning America' today (18.11.13), she explained why she wrote the book, which hits the shops on Tuesday, revealing: "Over the past few years, I've done this thing - a morning meditation basically, where I read out of a book and it's a quote, a passage and then a goal for the day.
"So basically what I wanted to do was do that for my fans. It's really cool. There [are] quotes in there all the way from Einstein and Aristotle, to Nicki Minaj and Tupac [Shakur]. It's crazy."