Teenagers who smoke contraband cigarettes are more likely to use illicit drugs, according to a recent study.

Researchers from the University of Alberta found that 31 percent of adolescent smokers in Canada between grades 9 and 12 use contraband tobacco and their findings indicates that teens who smoke contraband tobacco are more likely to use illicit drugs.

"The rate of illicit drug use among the contraband smokers is higher than that among teenagers who smoke non-contraband cigarettes--sometimes double or triple the rate," researcher Mesbah Sharaf said in a statement.

For the study, researchers collected and analyzed data from a national sample of more than 2,000 current smoker students in grades 9 to 12 from the 2010-2011 Youth Smoking Survey conducted by Statistics Canada. The survey assessed students' past-year use of the following drugs (including some street names for each type of drug): amphetamines, cocaine, hallucinogens, heroin, ecstasy and ketamine.

Based on the findings, 22 percent of all adolescent smokers in Canada used cocaine. Among those who smoked contraband cigarettes, 31 percent reported using cocaine, whereas only 18 percent of non-contraband smokers reported using cocaine. Use of ecstasy was also more prevalent among contraband smokers (45 percent) than among non-contraband smokers (33 percent). The rate of ketamine and amphetamine use among the contraband-smoking teens was almost three times as high as the rate among non-contraband-using teens -- and more than six times as high for heroin.

"If, as we believe this study shows, contraband cigarette use is associated with illicit drug use, then intensive effort needs to be made to avoid this -- by both government and tobacco companies," Sharaf said. "Adolescence is a critical period, and most unhealthy habits are developed at an early age."

Sharaf is calling on the federal government to strengthen contraband enforcement and enhance public education efforts to combat this trend.

"This is an important insight, and we encourage the government to come up with measures to tackle this problem," he said.

The findings are published in The Journal of Primary Prevention.