In this book, the authors gather and present current research in the study of the principles, analysis and benefits of screening tests. Topics discussed include the development of a screening instrument to detect common mental disorders in long-term sickness absence; a vision screening test in new-borns; nailfold capillaroscopy as a basic screening tool in Raynaud's phenomenon; the Profile of Moods Scale to assess six dimensions of mood; the Audio Recorded Cognitive Screen (ARCS) as a flexible and versatile instrument of clinical and research settings.