Neil Young has given up smoking marijuana and drinking alcohol to write his forthcoming autobiography ‘Waging Heavy Peace’.

“I did it for 40 years,” the singer told the New York Times. “Now I want to see what it’s like to not do it. It’s just a different perspective.”

The 66-year-old said he has been sober for about a year and quit smoking dope about the same time, Young used to smoke marijuana “the way others smoke cigarettes,” David Carr wrote in the NYT.

“The straighter I am, the more alert I am, the less I know myself and the harder it is to recognise myself,” Young explains in his forthcoming memoir, which he describes as elliptical and personal, with little of the period poetics of “Just Kids,” by Patti Smith, or the scabrous detail of “Life,’’ by Keith Richards.

Ironically, Young’s next album could end up his most mind-altering. ‘Psychedelic Pill’ features some of his longest jams, including a 28-minute track called ‘Driftin’ Back’.

‘Psychedelic Pill’ is Young’s first album of all new material with Crazy Horse since 2003 and will feature the full Crazy Horse line-up of Billy Talbot, Ralph Molina and Frank Sampedro.

The Neil Young Times states that the album was recorded straight after the band finished their ‘Americana’ sessions at the Audio Casa Blanca studios.

The album will be available on double CD and triple vinyl and full-length videos for each of the LP’s tracks will be previewed online.

Waging Heavy Peace is published in the US on 25 September. Psychedelic Pill is released on 29 October.