Scientists recently pinpointed the region of the brain that is linked with addiction, opening up many new opportunities to potentially treat addictions like tobacco or alcohol. In two studies, researchers found that smokers who suffered a stroke in the insular cortex were significantly more likely to quit smoking and experience fewer and less severe withdrawal symptoms than those who experienced strokes in other regions of the brain.
The studies were published in the scientific journals Addiction and Addictive Behaviours.
“These findings indicate that the insular cortex may play a central role in addiction,” said Amir Abdolahi from Philips Research North America and lead author of the research when he was a doctoral student at the University of Rochester School of Medicine and Dentistry. “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.”
Researchers tested the theory by looking at smokers who have had their insular cortex damaged from a stroke and its relationship with their ability to quit. Involving 156 stroke patients who were also active smokers, the study based their analysis around two sets of indicators: whether the patients resumed smoking after the stroke and the severity of their cravings during their hospitalisation. Each patient was given MRI or CT scans to determine the location of their stroke, then they were placed in two groups depending on whether or not it took place in their insular cortex. While the patients recovered in the hospital, researchers measured their individual levels of smoking withdrawal, since hospitalisation effectively means a guaranteed period of forced abstinence.
The researchers found that patients who experienced strokes in the insular cortex were subjected to fewer and less intense withdrawal symptoms than those with strokes in other parts of the brain. The researchers then followed the participants for another three months to measure the endurance of the stroke’s effects, finding that almost twice as many of the patients with strokes in the insular cortex quit compared to the other group of participants – an astounding 70 percent vs 37 percent.
The most prominent drugs that are currently used to treat tobacco dependence, like bupropion and varenicline, mostly target the brain’s ‘reward’ pathways by affecting the release of dopamine when its exposed to nicotine. Despite these drugs being generally effective, they rarely ever lead to the user quitting permanently. With this new research under their belt, scientists may be able to develop some form of drug that can dull the insular cortex’s response to substances the patient is dependent on.
Addiction, in a sense, is a form of illness. So maybe we’ll see a ‘cure’ for it in the near future.