Brain damage to insula may halt urge to smoking, findings appeared in the journal Science, published by AAAS.
The study was largely inspired by a patient who had smoked around 40 cigarettes a day before his insula was damaged by a stroke and then quit immediately after. He told the researchers that his body “forgot the urge to smoke.”
The insula receives information from other parts of the body and is thought to help translate those signals into something we subjectively feel, such as hunger, pain, or craving for a drug. Compared to other brain regions, the insula has not attracted very much attention in drug addiction research until now, but some imaging studies have shown that this region is activated by drug-associated cues, such as the sight of people doing drugs or drug paraphernalia.
“One of the most difficult problems in any form of addiction is the difficulty in stopping the urge to smoke, to take a drug, or to eat for that matter. Now we have identified a brain target for further research into dealing with that urge,” said study author Antoine Bechara of the University of Southern California and the University of Iowa.
Bechara and his colleagues studied 69 patients with brain damage who had been smokers before the damage occurred. Nineteen of these patients had brain damage that included the insula. Thirteen of the insula-damaged patients had quit smoking, and 12 of them had done so quickly and easily, reporting that they had felt no urges to smoke since quitting. The authors don’t know why the other six patients did not quit smoking. Some of the patients with other forms of brain damage also stopped smoking without effort, but, overall, patients who had quit easily were much more likely to have damage to the insula rather than anywhere else in the brain.
The discovery of the insula’s role in addiction opens new directions for therapies, Bechara said, including possible drugs targeted to a region that “no one paid attention to.” “There is a lot of potential for pharmacological developments”.
The finding raises the question of whether damage to the insula also could cause a person to quit other addictive behaviors. Can a brain lesion cure someone of their bad habits? Obviously brain damage is not a treatment option for nicotine addiction, but the new results may offer leads for therapies to help smokers kick the habit or for monitoring smokers’ progress while using existing therapies.