Better to prevent than to treat a dependency. In Germany they believe that campaigns in the field of universal prevention should be geared toward cross-substances. Germany has found that if they limit number of teens that take up smoking it also limits future cannabis use.

Certain measures of selective prevention have been successful. These programmes focus on a small minority of young people who use drugs in a way that may develop into problematic behaviours. Such a focus on vulnerable groups and settings are very important because measures for universal prevention don’t always reach them.

Both of these preventative measures should dovetail with one another. For example, cannabis is the most widely used illicit drug among young as well as older people. (However, she noted that evidence of medical benefits of cannabis are growing so both the risks and benefits should be studied.) Adolescents are the main target group of cannabis prevention. Web-based prevention need not only supply information. Certain interactive possibilities include text that shows how each user rates the risks of individual use patterns. Also provides on-line diary for people to record their own use patterns to be analysed by experts. These experts also provide advice on how to “kick their habits.” Another programme targets youth who have come into contact with police. All these programmes are evaluated by independent institutions.

Yet the possibilities of targeted and selective prevention programmes have not not been studied as much as they could.