Teens smoking cigarette
Teenagers smoke and talk in front of a vacant business in Ushuaia, Argentina, December 31, 2010. Reuters

A small study suggests that teen smokers desire nicotine because their brains respond differently when seeing someone smoke as compared to adults. The new findings say that a teen's brain has heightened responses in regions that are rich in dopamine, a neurotransmitter that modulates pleasure, regulates emotions and reward centres.

“We interpret these data to mean that the teen brain is more responsive to the rewarding and thrilling aspects of smoking, thus making craving more psychologically salient to them,” co-author Adriana Galvan of the University of California Los Angeles told Reuters Health. “The dopamine system undergoes significant maturation during the teenage years, rendering the teen brain more reactive to rewards and perhaps more vulnerable to addictive substances.”

The study, published in the Journal of Adolescent Health, involved analysing the magnetic resonance imaging (MRI) scans of smoking and non-smoking 39 teens and 39 adults. This allowed the researchers to observe how the participants’ brains react when watching videos of adolescents and young adults smoking.

Participants who smoke claimed to crave smoking after watching the video clips. Adolescent smokers stated the same level of craving as adults, even though they had been smoking for a shorter time.

According to the researchers, the connection between the activation of reward and pleasure centres and wanting to smoke cigarettes was only observed in teens. This was based on the MRIs studied after the team asked the participants how badly they wanted to smoke.

The researchers admitted that they did not ask the participants to hold back from smoking before the start of the study, which may explain the cravings. The team also speculated that older participants did not identify with the video clips featuring young people, hence the differences in responses.

Adam Leventhal, director of the Health, Emotion and Addiction Laboratory at the University of Southern California, explained that teens were more interested in seeking out new and exciting experiences compared to adults. This pleasure-seeking mindset significantly contributes to addictive behaviours like smoking.

Dr. Nancy Rigotti, a researcher at Harvard University and director of the Tobacco Research and Treatment Centre at Massachusetts General Hospital in Boston, added that setting the legal age to buying cigarettes at 21 years was reasonable. Rigotti noted that while this study does not necessarily prove that teens’ brains are more sensitive to nicotine, it provides data to support the claim.