Over the past decade energy drinks have risen to prominence with ads promising to give workers that extra boost they need after lunch or jack up customers’ mood to “extreme” levels. Teens a big market for such products, and now a new study has shown that energy drinks could have more far-reaching effects than just being possibly unsafe.

The study, published in the Journal of Addiction Medicine, has linked energy drink use in teens with alcohol and drug use. Researchers found that teens who consumer energy drinks were over two times more likely to report alcohol, cigarette, and illegal drug use.

The study also found that around 30% of teens consume energy drinks or energy shots. Boys are more likely to consume energy drinks than girls, as are children who come from broken homes or homes in which parents are less educated. Soft drinks, which 40% of teens say they drink every day, were also associated with drug/alcohol use, though the correlation is smaller.

Though the study found clear links between energy drink consumption and drug abuse in teens, it’s not entirely clear that energy drinks themselves are gateway drugs. Instead, the study’s authors believe that the marketing for energy drinks and caffeine itself may be selecting for teens more likely to use alcohol and drugs. Teens who are “sensation-seeking or risk-oriented” may be more likely to seek out the rush that high doses of caffeine can give.

“The current study indicates that adolescent consumption of energy drinks/shots is widespread and that energy drink users also report heightened risk for substance use,” wrote the study’s authors. “”Education for parents and prevention efforts among adolescents should include education on the masking effects of caffeine in energy drinks on alcohol and other substance-related impairments, and recognition that some groups (such as high sensation–seeking youth) may be particularly likely to consume energy drinks and to be substance users.”