The concept of mental health is still widely discussed among philosophers and scientists. The emphasis on positive emotions and functional aspects of the World Health Organization definition, which describes mental health as: "A state of well-being in which the individual realizes his or her own abilities, can cope with the normal stresses of life, can work productively and fruitfully, and is able to make a contribution to his or her community” has sometimes been called into question. This paper will focus on recently proposed mental health definitions, and in particular on mental health normative criteria involved in each of them. The criteria are divided in two broad categories: biomedical and cultural criteria. Strengths and weaknesses of each definition are illustrated in order to highlight research needs likely to support further progress.