Study: Brain areas work differently for smokers and drinkers

Shanghai scientists have located brain areas corresponding to smoking and drinking, bringing new insights and opening possibilities for stopping addictive behavior.

They found that regular smokers tend to have low functional connectivity, especially in the brain area associated with the processing of punishment, while those who drink often have high brain connectivity, especially in the reward-related brain area.

As human behavior is often guided by the desire to obtain positive outcomes and avoid negative consequences, neuroscientists are particularly interested in areas of the brain that process those things.

The research "showed that the abnormal connectivity of certain areas may be a factor attracting individuals to smoking and drinking", said Feng Jianfeng, leader of the team from the Institute of Science and Technology for Brain-Inspired Intelligence affiliated with Fudan University.

The team also found a correlation between smoking, drinking and impulsiveness. Changes in functional connectivity in the brain area associated with impulsive behavior could be observed.

"It suggested that being impulsive may be a factor leading to smoking and drinking, or vice versa," said Cheng Wei, the lead author of the research.

The researchers said that the extent of such functional connectivity changes in the brains of drinkers and smokers is closely related to the amount of alcohol and nicotine they consume.

"Such changes are even detectable in the brains of individuals who smoke only a few cigarettes or drink a little," Cheng said.

The research was based on a modeling analysis of brain networks using nearly 2,000 magnetic resonance imaging (MRI) samples. The samples included daily smokers, nonsmokers, alcoholics and nondrinkers - as well as people who smoke or drink on occasion - from the United States and European countries.

A paper about the study was published on the website of the United Kingdom-based biomedicine journal eLife earlier this month.

Researchers said the findings could have significant public health implications, as drinking and smoking affect many people worldwide.

According to the World Health Organization, more than 1.1 billion people globally smoke tobacco, and more than 7 million die each year because of their use of tobacco. About 2.3 billion people drink alcohol often. Of those, more than 25 percent are between age 15 and 19. More than 3 million people die as a result of the misuse of alcohol each year.

The research team said its previous research on depression showed that changes in human brains were exactly opposite to those in drinkers and smokers.

"We found that depression sufferers have increased sensitivity to negative stimuli and reduced sensitivity to positive stimuli," Feng said.

"So we speculated that those who have smoking and drinking habits may be less likely to suffer from depression, or that a certain amount of smoking and drinking may alleviate depression symptoms," he said, adding that the team wants to figure out the reason for the opposite mechanisms.