Researchers Find Diminished Brain Volume in Adolescents Who Smoke
Neuroimaging indicates that individuals with a higher likelihood of taking up smoking during their teenage years tend to exhibit diminished gray matter in two critical brain regions. These findings suggest that these regions may have a substantial impact on inhibition and the development of addiction.
“Smoking stands as one of the most prevalent addictive behaviors globally and is a leading contributor to adult mortality,” states Trevor Robbins, a psychologist from Cambridge University. “The initiation of smoking is most likely to occur during adolescence. Any method for identifying an elevated risk of this behavior, allowing us to focus interventions, has the potential to save countless lives.”
Investigating Brain Scans and Personality Traits
An international research team, spearheaded by bioinformatician Tianye Jia from Fudan University and cognitive neuroscientist Shitong Xiang, conducted a comparative analysis of MRI brain scans obtained from over 800 individuals in the UK, Germany, France, and Ireland at various points in time. These volunteers also completed personality trait questionnaires.
Subsequently, the researchers contrasted those who commenced smoking by the age of 14 with non-smokers. They repeated this comparison when the same individuals reached the ages of 19 and 23.
The MRI scans unveiled that those who initiated smoking at 14 exhibited reduced gray matter in the left ventromedial prefrontal cortex, a brain region associated with emotional regulation, decision-making, and self-control.
Changes in the Brain Region Associated with Pleasure
Five years later, scans showed that the opposite side of this same brain region (on the right) was also diminished in the group of smokers in comparison to non-smokers. This particular part of the ventromedial prefrontal cortex has been linked to pleasure.
“The ventromedial prefrontal cortex serves as a crucial area for dopamine, the brain’s pleasure neurotransmitter,” explains psychiatrist Barbara Sahakian from Cambridge. “Dopamine has long been associated not only with pleasurable experiences but also with its impact on self-control.”
The results from the questionnaires may offer some insights into why this occurs.
“Both questionnaires assess the pursuit of exciting experiences, but they capture different behaviors,” Robbins elaborates. “The sensation-seeking scale focuses on enjoyable experiences, whereas the novelty-seeking questionnaire includes items related to impulsivity and rule-breaking.”
Participants whose responses indicated a stronger inclination toward sensation-seeking tendencies were more likely to exhibit reduced gray matter on the right side of the ventromedial prefrontal cortex. Conversely, greater novelty-seeking tendencies were linked to diminished gray matter on the left side. These reductions in gray matter translate to decreased inhibitions and a greater inclination towards risk-taking behaviors, factors that elevate the likelihood of teenagers taking up smoking.
“Subsequently, smokers experience significant reductions in gray matter in the right frontal lobes, which is associated with behaviors reinforcing substance use,” notes Jia, underscoring the activation of the sensation-seeking pleasure mechanism. “This might provide a causal explanation for the initiation of smoking in young individuals and how it evolves into dependence.”
Brain Changes in Late-Onset Smokers
Another group within the study’s population consisted of individuals who initiated smoking at the age of 19. At the age of 14, this group exhibited reduced gray matter in their left prefrontal cortex, but their right side displayed no differences compared to non-smokers until they began smoking.
This observation suggests that a decrease in gray matter in the left frontal lobe might be a hereditary indicator for individuals with inclinations toward addiction.
To address this issue, Jia and colleagues propose that offering alternative non-drug incentives during the initial stages of substance use might help deter the progression toward substance dependence.
The researchers are also eager to determine if their findings hold true in the case of vaping.
Smoking is attributed to one in five adult deaths in the United States. Identifying those at the highest risk before they even begin could have a transformative impact on their lives.
Read the original article on: Science Alert
Read more: ‘Airpocalypse’ Smoke Reaches North Pole for the Very First Time
