In April 2001, filmmakers Joe Berlinger and Bruce Sinofsky began following Metallica to document the recording process of the band's next studio album. Over two years they recorded more than 1,000 hours of footage. On July 19, 2001, before preparations to enter the recording studio, Hetfield entered rehab to treat his "alcoholism and other addictions". All recording plans were put on hold and the band's future was in doubt. Hetfield left rehab on December 4, 2001, and the band returned to the recording studio on April 12, 2002. Hetfield was required to limit his work to four hours a day between noon and 4 pm, and to spend the rest of his time with his family. The footage recorded by Berlinger and Sinofsky was compiled into the documentary "", which premiered at the Sundance Film Festival in January 2004. In the documentary, Newsted said his former bandmates' decision to hire a therapist to help solve their problems which he felt they could have solved on their own was "really fucking lame and weak".