The World Health Organization suggests mental ill health in terms of depres- sion soon to be the highest-ranking disease problem in the Western part of the world. However, some critics argue that the alarming reports on mental ill health have their ground in the methods of inquiry themselves and refer to medicalization as an important issue. The aim of this article is to explore and illuminate the issue of what is meant by mental health and mental ill health and what it means that mental ill health is a major public health problem. Basically two understandings and aspects of public health exist: a ‘reductionist’ and a ‘holistic’ with connections to different theories of health. These diverging un- derstandings may lead to quite different pu...