Video: Why "Just Say No" Just Won't Work

Telling people to "just say no" to their vices is wishful thinking, the head of the National Institute on Drug Abuse says in a 60 Minutes report this weekend. Dr. Nora Volkow emphasizes that addiction happens on a neurological level, and she should know; she works with MRI scans that show how the brains of addicts alter, making it difficult for them to resist narcotics, food or whatever else they're hooked on. "We know that drug addiction is a chronic disease... drugs change the brain, physically change it," she says in the preview [below]. And the changes apparently remain long after an addict stops using. The level of dopamine—the brain chemical connected to pleasure—in an addict's brain spikes if they even just look at a photo of the substance they abuse, just as a hungry person gets hungrier at the sight of food. "It just basically stimulates release of dopamine and the more they release, the more they want the food," Volkow says. "We always say, 'Well, why do we have a problem with obesity in our society?' And I said, 'My God, we are surrounded by stimuli with which we are conditioned. If you like hamburgers, you may see that McDonald's yellow arches and then dopamine goes inside your brain and you want it and you don't know why you want it." The 60 Minutes report airs Sunday April 29 at 7 pm ET/PT.