Epidemiological findings indicate that up to 18.5 % of the German adolescents suffer from depressive symptoms and that younger adults display the highest risk for relevant symptoms of depression (9.9 %) within the German adult population. Internet-based interventions have been shown to be useful for preventing and treating depression and are more easily disseminated in internet-savvy generations. Available programs are usually based on principles of cognitive behavioural therapy. They differ significantly with regard to target groups, structure, content, degree of guidance provided by online-coaches and evidence for their efficacy. Whereas some studies could not prove the use of the trainings there are others that show large effect sizes (up to d = 0.84) for the reduction of depressive symptoms. In Germany there are some online counseling programs for children and adolescents in (acute) crises available. However, at this point no structured intervention program for the treatment of depression exists.