Modern psychology and modern medicine have addressed the impact of physical illness on the mental health of the individual and concentrated in prevalence on repairing injuries and treating disorders. Their frame of reference has been a disease-based approach. In the years after World War II, psychology’s main objectives became to cure mental pathologies, to increase the productivity and satisfaction of individuals and restore them to their families, and to a much lesser extent to identify and cultivate their strengths. In second half of the 20th century, however, a revolutionary change took place in our understanding of health. The parameters of health, until then consisting of morbidity, mortality, infant mortality and lifespan, were expanded to measure not only the absence of health, but also its presence. In other words, the very definition of health was modified. In 1948, the World Health Organization revised the concept of health to include social, cultural and subjective dimensions (Houweling, Kunst, & Mackenbach, 2001). The definition of the health was no longer the mere absence of disease, but a complete state of physiological, psychological and social well-being (McGregor, 1992).