Teenagers who smoke tobacco to “feel better” may actually be at increased risk for depressive symptoms, Science Daily reported Aug. 27.

Canadian researchers asked 662 high-school students to fill out questionnaires over a five-year period on their use of smoking to improve mood (“self-medication”). The students were also asked about depressive symptoms — e.g., excessive worry, feelings of hopelessness, and sleep problems.

Researchers found that teens with higher self-medication scores related to smoking had more depressive symptoms than those with lower scores and those who didn’t smoke. 

“Although cigarettes may appear to have self-medicating effects or to improve mood, in the long term we found teens who started to smoke reported higher depressive symptoms,” said Michael Chaiton, researcher at the Ontario Tobacco Research Unit of the University of Toronto and lead author of the study.

The study is available online in the journal Addictive Behaviors.