Doubleday published "A Million Little Pieces" in April 2003, which Frey wrote and marketed as a memoir of drug addiction, crime, and an eventual journey to sobriety. Initial reception was mostly positive, with Amazon.com editors selecting it as their favorite book of that year; and Frey followed it up with the sequel "My Friend Leonard" in 2005. The second book centered on the father-son relationship which Frey formed with his friend Leonard, from the Hazelden addiction treatment program. "My Friend Leonard" was published in June 2005 by Riverhead and became a bestseller. Significant parts of the two books, initially promoted as factual, later were revealed to have been invented by Frey (see ).