A new study links teenagers’ use of Ecstasy and speed (methamphetamine and/or amphetamine) with a higher risk of developing depression. The study did not prove the drugs caused depression, according to HealthDay.

The study of almost 3,900 10th graders in Quebec found that, compared with teens who didn’t use the drugs, those who said they used either speed or Ecstasy had a 60 to 70 percent increased risk of showing signs of depression a year later. Those who had tried both speed and Ecstasy had twice the risk for developing depressive symptoms, the researchers report.

They note the drugs could have an effect on hormone levels involved in mood control. It is also possible that those who use the drugs are influenced by other users who have their own issues and mood problems.

“Our findings are consistent with other human and animal studies that suggest long-term negative influences of synthetic drug use,” co-author Frédéric N. Brière of the University of Montreal said in a news release.

The study is scheduled to appear in the Journal of Epidemiology and Community Health.