Brain Damage Gives Clues On How To Quit Smoking With Ease

US Scientists have discovered that when a small area of a smoker's brain is damaged it often makes them quit smoking easily. It is possible that this discovery could lead to treatments that target that same area of the brain to help smokers give up the habit.

The study is published in the current edition of Science.A neuroscientist at the University Southern California in Los Angeles, Dr Antoine Bechara, conducted the study with two colleagues.Dr Bechara and colleagues have been looking at the brains of 19 smokers who had suffered damage to the insula. In 6 of the smokers the damage was to the right part of the insula, in the remaining 13 it was to the left. Their insula damage was the result either of a stroke or surgery, for instance to remove tumours. The insula is a small part of the brain that lies deep inside one of the folds of the cerebral cortex, the outermost region of the brain that is responsible for complex processes like memory, thinking and language (also known as grey matter).Previous studies have suggested that the insula plays a key role in developing and maintaining addiction urges. For instance when drug addicts see images of drug taking equipment, the insula shows increased activity in brain scans. The same effect occurs in the brains of smokers when they are shown a film of people smoking.Of the 19 smokers, Dr Bechera and colleagues discovered that 12 of them had abruptly stopped smoking directly after their injury. They had no further urges to smoke and did not smoke again. One ex-smoker, who had been on 40 unfiltered cigarettes a day before his stroke said "my body forgot the urge to smoke". He said he had had no desire to quit before his stroke.The researchers compared this to a group of 50 smokers who had suffered brain damage, but not to the insula. Although 19 of them did quit, only four of them stopped with as much ease.Dr Bechara and colleagues classified the permanence and ease of cessation in the two groups. The highest score of permanence and ease would be given to a person who quit within a day of suffering the brain damage, who did not start again, who found it easy (on a scale of 1 to 7 they rated the difficulty as less than 3), and they had no urge to smoke. On this basis they found that only 4 of the 19 in the non-insula damage group qualified as having stopped with the same level of ease as the insula-damaged quitters.In both groups, the insula damaged and the non insula damaged, the patients had been smoking at least 5 cigarettes a day for 2 years. In both groups the average age at time of brain damage was over 45, and their average age at the time of the study was 55. Edythe London, neuropharmacologist at the University of California, Los Angeles, says in the same issue of the journal that this discovery helps to understand what happens in the brains of addicts. It lends support to the idea that the insula plays an important role in regulating the emotional responses involved in addiction. She goes on to say that "Gut feelings that are associated with cravings are probably only experienced after the information is processed in the insula". Bechera and colleagues hope that these findings will help toward treatments to beat addiction, not only to nioctine and cigarettes but to other substances too.(Source: Science : University Southern California in Los Angeles : February 2007.)