TUESDAY, Nov. 2 (HealthDay News) -- A certain area of the cerebral cortex is thinner in smokers than in people who have never smoked, finds a new study.

The cerebral cortex is an area of the brain that plays an important role in reward, impulse control and decision making.

German researchers obtained high-resolution 3-D images of the brain structures of 22 smokers and 21 people who never smoked. Using these images, the scientists calculated the thickness of the cerebral cortex in each participant.

On average, smokers had a thinner medial orbito-frontal cortex than nonsmokers. The thickness of this region decreased in relation to heavier daily consumption of cigarettes and the number of years a person had been a smoker.

However, a direct cause-and-effect isn't clear, said the team at the Charite Universitatsmedizin Berlin and of the Physikalisch-Technische Bundesanstalt (PTB), the German National Metrology Institute.

They said further research is needed to determine whether smoking causes this region of the brain to become thinner or whether people who have a thinner cortex region by nature are more likely to become smokers.

The study appears in Biological Psychiatry.

More information

The American Cancer Society has more about smoking, tobacco and health.