The pop star feared she was in a downward spiral after the band shot to fame in 2008, but she was pulled back from the brink of self-destruction by her friends in the girl group.
White, who has now replaced partying with trips to the gym, tells British magazine Hello!, "The great thing about being in a band with other girls is that we are so close. We're very honest with one another and we will sit each other down and say, 'This is getting out of control'.
"If I hadn't had them, it would have been so easy to have gone off the rails and kept up the partying until it became a problem. You need people around you to say, 'Right, this is too much now,' and fortunately I have that."