Scientists have identified the insular cortex as the portion of the brain that could be vital in getting people to stop smoking as well as treat other kinds of addiction.
Based on the results of two studies, researchers found that smokers who suffered a stroke in the insular cortex were more likely to quit and experience withdrawal symptoms that are fewer and less severe compared to those who have had strokes in other parts of their brain. The findings of these studies were published in Addiction and Addictive Behaviors.
Lead author Amir Abdolahi said: “These findings indicate that the insular cortex may play a central role in addiction.” The research Abdolahi conducted was done when he was a doctoral student at the University of Rochester School of Medicine and Dentistry.
Abdolahi, now at Philips Research North America, said that “When this part of the brain is damaged during stroke, smokers are about twice as likely to stop smoking and their craving and withdrawal symptoms are far less severe.”
Currently, the frontline prescription drugs – such as buprion and varenicline – being used treat tobacco dependence. These drugs target mainly the “reward” pathways of the brain by meddling with the release and binding of dopamine in the brain in response to nicotine. Although these drugs achieve their intended effects, they aren’t real guarantees for quitting. In fact, they have high rates of relapse.
The insular cortex, which is a central region of the brain, may also have a vital role in the cognitive and emotional processes facilitating drug and tobacco use, according to recent studies.
Researchers involved in the addiction studies tested this theory. They tried to determine whether smokers with a damaged insular cortex were more likely to quit smoking. To do this, they looked at tow different set of indicators: did patients resume smoking after a stroke and how severe their craving was for cigarettes when they were hospitalized.
For the study, 156 stroke patients were involved. These patients were identified as active smokers and were admitted to three hospitals. MRI and CT scans were used to determine the location of the stroke for each patient.
The patients were then divided into two groups: those whose stroke occurred in the insular cortex and those whose stroke happened in another part of the brain.
Researchers then measured the level of smoking withdrawal of these patients while they were recovering in the hospital. Now, hospitalization does require patients to refrain from smoking for a certain amount of time. This was the kind of environment ideal for the measurement of how severe a patient’s withdrawal symptoms were.
Results of the study showed that patients who had a stroke in the insular cortex had less severe, as well as fewer, withdrawal symptoms compared to those who had a stroke in other areas of the brain.
The patients involved in the study were further monitored by the researchers for three months in order to determine whether they had taken up smoking again or not. The results? 70% of those who suffered a stroke in the insular cortex quit smoking compared to 37% of those who had a stroke in another part of the brain.
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