Spot in brain may control smoking urge

A stroke patient may have revealed a key to understanding craving:

Damage to a silver dollar-sized spot deep in the brain seems to wipe out the urge to smoke, a surprising discovery that may shed important new light on addiction. The research was inspired by a stroke survivor who claimed he simply forgot his two-pack-a-day addiction - no cravings, no nicotine patches, not even a conscious desire to quit.

"The quitting is like a light switch that went off," said Dr. Antoine Bechara of the University of Southern California, who scanned the brains of 69 smokers and ex-smokers to pinpoint the region involved. "This is very striking."

Clearly brain damage isn't a treatment option for people struggling to kick the habit.

But the finding, reported in Friday's edition of the journal Science, does point scientists toward new ways to develop anti-smoking aids by targeting this little-known brain region called the insula. And it sparked excitement among addiction specialists who expect the insula to play a key role in other addictions, too.

"It's a fantastic paper, it's a fantastic finding," said Dr. Nora Volkow, director of the National Institute on Drug Abuse and a longtime investigator of the brain's addiction pathways.

"What this study shows unequivocally is the insula is a key structure in the brain for perceiving the urges to take the drug," urges that are "the backbone of the addiction," Volkow added.

Why? The insula appears to be where the brain turns physical reactions into feelings, such as feeling anxious when your heart speeds up. When those reactions are caused by a particular substance, the insula may act like sort of a headquarters for cravings.