Young, non-daily smokers experience symptoms of nicotine addiction but often fail to make the connection between cigarettes and the signs of growing dependence, a new study finds.

For new smokers, “an urge to smoke or being irritable because they are not able to smoke is a sign of early dependence. But they don’t seem to recognize that symptoms such as irritability are harbingers of addiction,” said researcher Chyke Doubeni, M.D., of the University of Massachusetts.

The study, which tracked adolescents for a four-year period, found that nondaily smoking can lead to early symptoms of nicotine dependence, which in turn can prompt more cigarette use and, eventually, addiction.

The findings were reported by News-Medical.net on May 4 and published in the journal Pediatrics.