"CAN Stop"--implementation and evaluation of a secondary group prevention for adolescent and young adult cannabis users in various contexts--study protocol.

Background: Current research shows that overall numbers for cannabis use among adolescents and young adults dropped in recent years. However, this trend is much less pronounced in continuous cannabis use. With regard to the heightened risk for detrimental health- and development-related outcomes, adolescents and young adults with continuous cannabis use need special attention.