Background. Mood and anxiety disorders are highly prevalent and have a large impact on the lives of the affected individuals. Therefore, optimal treatment of these disorders is highly important. In this study we will examine the effectiveness of a stepped care program for primary care patients with mood and anxiety disorders. A stepped care program is characterized by different treatment steps that are arranged in order of increasing intensity. Methods. This study is a randomised controlled trial with two conditions: stepped care and care as usual, whereby the latter forms the control group. The stepped care program consists of four evidence based interventions: (1) Watchful waiting, (2) Guided self-help, (3) Problem Solving Treatment and (4) Medication and/or specialized mental health care. The study population consists of primary care attendees aged 18?