Damage to insula in brain makes people forget to smoke.

An intriguing discovery: people with damage to an area of the brain called the insula are much more likely to quit smoking. 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 results are very preliminary. Dr. Antoine Bechara of the University of Southern California and his colleagues identified 19 smokers who had experienced some degree of brain damage, resulting in lesions on the insula. Of these, 13 quit smoking. The scientists also identified 50 smokers whose brain injuries did not include damage to the insula, 19 of which quit smoking.

"Participants with damage to the insula were overwhelmingly more likely to experience a true disruption of the urge to smoke, characterized by an almost immediate cessation of smoking with no reported struggles to maintain their abstinence," said Dr. Bechara. 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. We already know from some imaging studies that the insula is activated by drug-associated cues, such as the sight of people doing drugs or drug paraphernalia.

Obviously, no one is suggesting that brain damage be used as a treatment. What can be suggested from this study are two things:

• We can identify/invent ways to disrupt the function of the insula. One approach is to search for insula-targetting drugs, hopefully identifying some (one) that inhibit its function. Another suggestion is what's called transcranialmagnetic stimulation, a technique where weak electrical currents are induced in the brain tissue to disrupt the insula's activity; however, currently, the currents do not penetrate deep enough to reach the insula, and so we'll need more progress before this becomes a viable option.
• More presently, perhaps we can monitor insular activity as a means to track the progress of smokers trying to quit using current methods. If I were a smoker, the thought of weekly visits to an MRI machine would be enough to make me quit

The paper is in today's Science, along with some commentary.

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