The study, published in the Archives of Pediatrics & Adolescent Medicine, tested two dosages of the medication -- buproprion -- and a placebo in a clinical trial.

University of Arizona, Tucson researchers Dr. Myra Muramoto and Scott Leischow, randomly assigned the participants -- 312 smokers age 14 to 17 who had already tried to quit before -- to receive either 300 milligrams of the medication, 150 milligrams, or a placebo. All received weekly counseling.

Nearly 6 percent of those in the placebo group, 11 percent of those in the 150-milligram group and 14 percent of those in the 300-milligram group had quit smoking.

End-of-treatment abstinence rates lower than those seen in adults and high relapse rates after stopping medication suggest doubling the treatment period to the 12 weeks recommended for adults, the researchers say.

"Nonetheless, this study provides hope for helping a generation of smokers quit before they become adults," the authors say in a statement. "These results are critically important because few effective treatment options are available for adolescent smokers who want to quit."