John Mayer always keeps a supply of Xanax handy

Rocker John Mayer admits he always keeps a supply of anti-anxiety drug Xanax handy.

The Grammy winner, who has dated the likes of Jessica Simpson and Jennifer Love Hewitt, told Best Life magazine that he first experienced an 'anxiety bender' in his early 20s.

"There are these incidental kinds of loopholes in my brain, where the wires can cross for a second and the hard drive crashes," he told the magazine.

"You can create dark neighborhoods in your mind as easily as you can create rural wonderlands."