The toxic chemicals in crystal methamphetamine literally eat away brain tissue. The brain on the left is normal and the brain on the right is of a 28-year-old meth user.

"[Crystal meth] literally puts holes in your brain," Debra Jay explains. "Remember how Chantel was talking about her drug addiction? Just like it was nothing. You absolutely lose the ability to learn from past mistakes or to care about anything. And it's not because she's being bad. It's because her brain no longer works. And this can be permanent. That's why it was so important to get her into treatment."

Methamphetamine addicts go days without sleeping or eating and get what Debra Jay calls "a drug-induced anorexia." Malnourished, the body starts eating itself. First fat, then it starts eating muscle…