In the past Generalized anxiety disorder (GAD)--previously classified as anxiety neurosis--was regarded as not being a separate diagnostic entity. On the basis of new explicit criteria for GAD in the 90ies, GAD-specific pharmacological (i.e. SNRI) and psychological treatments with improved efficacy have become available. The Generalized Anxiety and Depression in Primary care study (GAD-P) investigates the prevalence of GAD in primary care settings and evaluates the patterns of care provided. Aims, methods and findings of the GAD-P study are described in this supplement.