Ash were "going through complete nervous breakdowns" when their new documentary was made.
The 'Burn Baby Burn' band were just teenagers when they achieved fame with their debut album '1977' and the period around the recording and release of the album is the subject of the new documentary, called 'Teenage Wildlife'.
Frontman Tim Wheeler explained: "It was hard for me to watch it for a while as we were going through complete nervous breakdowns trying to deal with it all as we were so young.
"But it's a really cool document of that whole time especially as it was a lot harder to make documentaries on the road back then and there was a lot of craziness."
The film is narrated by actor Ewan McGregor and has a script written by late journalist Steven Wells. As well as the recording of '1977' the documentary follows the group on their debauched subsequent tour of America.
The release of the documentary on October 17 coincides with the release of a new compilation 'The Best of Ash'.