Demi Lovato's drug battle began at 12

Demi Lovato's substance abuse issues started when she began guzzling painkillers at the age of 12.

In 2010, the Heart Attack hitmaker checked into rehab to battle her drug demons and personal issues, and she now admits the problems started at a young age.

The pop star was involved in a car accident when she was 12 years old and suffered minor injuries which led to doctors prescribing her painkillers.

Lovato insists that was the catalyst for her drug addiction, telling Britain's You magazine, "That was how the substance abuse started. I liked the feeling they gave me - they sort of numbed everything - and I also liked the sneakiness of taking extra pills out of my mom's bag without her knowing."

The addiction spiralled out of control, and Lovato confessed to taking cocaine onto planes so that she wouldn't have to go without her fix, adding, "I would smuggle it on and just wait until everyone in first class was asleep and then I would sneak to the bathroom."