Scientists Discover Genetic Link to Nicotine Addiction
There’s no denying that nicotine is addictive, but a new study shows that some people might be more likely to get addicted to nicotine than others. Scientists found that some individuals are simply more vulnerable to addiction and can easily become hooked on cigarettes after just one smoke. It seems the level of vulnerability is determined by a genetic trait.
Scientists at John Hopkins University School of Medicine decided to investigate how people react to nicotine on their first exposure to get a better look at how genetics might play a role. After giving nicotine to a group, some people were clearly more prone to addiction and gravitated towards repeated use while others seemed to avoid further use completely.
“From an addiction point of view, nicotine is a very unusual drug,” said Professor Roland Griffiths. “When you give people nicotine for the first time, most people don’t like it. It’s different from many other addictive drugs, for which most people say they enjoy the first experience and would try it again.”
Griffiths and his research team recruited 18 individuals who had never smoked in the past and they gave them each a pill. Some of the pills contained a low dose of nicotine and the others were placebos. The nicotine pills were actually dosed ten times lower than the dose found in a regular cigarette. It was just enough for the individuals to experience an effect such as better focus, increased energy, mood changes, jitters, or relaxation.
Participants were told the pills could contain a variety of substances like caffeine, sugar, ginseng, chamomile, kava, theobromine, and nicotine. Each day, the participants were given one nicotine pill (called pill A) and one placebo (pill B) with a minimum of two hours between each dose. The researchers mixed up the order that the pills were given each day. After each dose, participants had to report any symptoms they experienced.
After 10 days, participants were asked if they could distinguish differences between pill A and pill B and if they couldn’t tell the difference, the researchers increased the nicotine dosage slightly. Once the participants could all identify whether they were receiving pill A or pill B, they were allowed to choose which pill they wanted.
Interestingly, some of the participants believed the placebo pill contained a drug and associated that pill with symptoms like drowsiness. Half of the participants consecutively chose the nicotine pill because they experienced positive effects such as increased energy, better mood, improved concentration, and alertness. The other half opted for the placebo because they felt the other pill made them dizzy, sick, or light-headed.
Professor Griffiths believes genetic and metabolic differences between participants are largely responsible for their reactions to the nicotine pill. Those who chose to voluntarily take nicotine over a placebo are likely more prone to addiction. Through further studies, Griffith hopes to better understand how to help people who are more likely to be addicted. “I hope our findings will point the way toward future interventions that prevent or treat nicotine addiction, a topic of increasing importance in light of the expanding marketing of electronic nicotine delivery devices – e-cigarettes – to youthful nicotine non-users.”
Are you surprised to learn that there could be a genetic component at work in nicotine addiction? How did you react to nicotine when you tried it for the first time?