First graders who misbehave in school may be more likely to be regular smokers as young adults, according to new study findings.

After following a group of first graders for 15 years, U.S. investigators found that among the kids who tried smoking, those who misbehaved were 66 percent were daily smokers.

These findings suggest that early action may stop some teens from picking up the habit, and abandoning it if they do, lead author Dr. Carla L. Storr of the Johns Hopkins University in Baltimore told AMN Health.

“Start early - pre-school and primary grades,” she said. “Parents and teachers need to pay attention to expressions of the mental and behavioral profile, such as misbehavior.”

In the American Journal of Epidemiology, she and her colleagues point out that previous research has shown that children with behavior or antisocial problems are more likely to use drugs later in life.

To investigate whether the same may be true for smoking, Storr and her team asked first grade teachers in mid-Atlantic public schools to report the behavior patterns of 1,692 of their students.

Children were rated as misbehaving according to whether they started fights, broke rules, stole, teased, were stubborn, yelled or hurt other people, or had trouble accepting authority.

The researchers contacted the subjects 15 years later and asked them if they had ever tried cigarettes or had become hooked on them. Dependence was measured according to, among other factors, how soon teens smoked after waking up, whether they found it difficult to hang out in non-smoking environments, and the number of cigarettes they smoked each day.

The researchers found that more than half of the former first graders said they had tried smoking at least once. Among these ever-smokers, 50 percent were not considered dependent, 31 percent were considered “moderately” dependent, and 19 percent were “more severely affected,” defined as needing to smoke right after they woke up and smoking even when they were seriously ill.

Among those who tried smoking in young adulthood, those with the highest level of behavior problems were significantly more likely to become seriously hooked on the habit.

Storr explained that the reasons why smoking is linked to early childhood bad behavior remain unclear, but some believe both are due to a third factor. For instance, genetic traits or early experiences may predispose a child to both behavior problems and a tendency to experiment with drugs, she noted.

Alternatively, Storr noted that some experts have proposed that kids who misbehave may be more likely to try cigarettes at a very early age, at a “critical developmental period,” which may make them more vulnerable to later addiction.

SOURCE: American Journal of Epidemiology, July 15, 2004.