Mental health, mental hygiene and mental wellness are all terms used to describe the absence of mental illness. By this definition, mental status has two possibilities: either health or illness.
The most intresting thing about mental health is that mental "disorders" have never actually been proven; they are voted in. (http://www.oikos.org/radchang.htm)
However other experts consider mental health as a continuum. Thus an individual's mental health may have many different possible values. Using this model, it has been suggested that mental wellness can be a positive attribute, such that a person can become more "mentally healthy", even if they do not have any diagnosable mental illness. This definition of mental health includes emotional well being, having the capacity to live a full and creative life and also the flexibility to deal with its problems. Many therapies and self-help books claim to be able to increase the mental wellness of otherwise healthy people.
Dr. William Glasser, M.D. and psychiatrist, a recognized authority in therapy and counseling, wrote his first book, Mental Health or Mental Illness (1961), referred to in that book as Mental Hygiene. In using that term he was following the dictionary definition of hygiene which is the establishment and maintenance of health, ie. mental health. Currently, many mental health professionals, focus more on medications than on mental health.
Mental Health as a concept completely separate from mental illness plays no part in what most mental health professionals actually do, relying almost completely on the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) using the medical model to diagnose and treat what they call mental illnesses and disorders.
For an informed discussion of this topic, Dr. Glasser has published Treating Mental Health as a Public Health Problem -- A New Leadership Role for the Helping Professions.(2004 -- www.wglasser.com )
Dr. Glasser defines mental health as an entity completely separate from mental illness, explaining that as long as the medical model prevails, we will be unable to deliver the mental health many people need at a cost they can afford. Dr. Glasser asserts that the Public Health Model is much better suited to delivering mental health than the Medical model.
The Public Health Model has been successfully delivering physical health to millions of people for hundreds of years. He explains how this model could be expanded into a low cost Public Mental Health Delivery Model that could easily be put into practice by all mental health professionals and institutions by hiring mental health professionals to deliver mental health without diagnoses and without drugs directly to people whose mental health needs improvement.
Dr. Glasser's work is closely associated with Choice theory.