Despite modern interventions, cigarette smoking remains difficult to quit, and relapse after an attempt at smoking cessation is common, in large part due to the many regions of the brain that play a role in addictive behavior. A new study from the University of Iowa published in the January 26 Science has identified a region of the brain - the insula - that may play an important role in the conscious urge to smoke and provide a potential target for new antismoking therapies.

Researchers compared 19 smokers who had experienced brain damage that included the insula with 50 smokers who had damage to other parts of the brain. They specifically assessed disruptions of smoking addition - cessation of smoking within 1 day of experiencing brain damage, a loss of the urge to smoke, ease in quitting, and lack of relapse to smoking.

Patients with damage to either the left or the right insula were significantly more likely to experience disruption of smoking addiction than those with damage to other regions. Twelve of the 13 patients who quit smoking after damage to the insula reported a disruption of smoking addiction, compared with only 4 of the 19 patients who quit smoking after damage to other regions of the brain. Damage to regions other than the insula was not significantly associated with disruption of smoking addiction.

The experience of their patients "suggests that the insula plays a role in the feeling that smoking is a bodily need," explained the authors. "Our findings suggest that therapies that modulate the function of the insula will be useful in helping smokers quit."