Findings from new research indicate that individual variations in brain chemistry may profoundly affect a person’s vulnerability to nicotine addiction, and adolescents who smoke may be predisposed to certain behavioral health disorders, ScienceDaily reported on Nov. 8.

“As the negative health consequences of smoking have become more and more obvious, the majority of smokers have attempted to quit, “says Marina Picciotto, PhD, of Yale University. “Unfortunately, people who want to quit often find that they cannot, and recent neuroscience research has identified many of the molecular mechanisms that lead to nicotine addiction.” 

Many people who smoke have behavioral health disorders, such as major depression, and find it much harder to quit, adds Picciotto.

Mice research led by Jerry Stitzel, PhD, of the University of Colorado, found that nicotine’s effects are at their greatest when corticosterone levels are at their peak, indicating that smokers smoke more when they are under stress.

A study using rats led by Carlos Bolanos, PhD, of Florida State University, found that nicotine exposure during adolescence resulted in behavioral deficits resembling depression and anxiety that can last into adulthood. These rats were less willing to explore new environments and showed greater anxiety. Further studies will explore the effectiveness of serotonin reuptake inhibitors, commonly used to treat depression, for reversing nicotine-induced behavioral effects.

A study led by Read Montague, PhD, of Baylor University, found that while both smokers and nonsmokers are strongly guided by rewards when they make decisions, smokers had more difficulty factoring in abstract “could have been” rewards. “The actual rewards take over, and the “could-have-beens” no longer have a say in one’s decisionmaking,” says Montague.