ABSTRACT
The conventional approach to defining diseases assumes that people either have or do not have a condition. It does not work very well for most mental health problems, as these are based on common sensations and perceptions that most of people experience from time to time. It is apparent that the various symptoms that make up the diagnostic categories of mental disorders are distributed widely and variously across the population. The biomedical model considers that pathophysiological changes are the basis on which to consider and characterize the presence of a pathological process. Disease categories should only be regarded as valid if they can be shown to be discrete entities with natural boundaries that separate them from other disorders. Even more uncertain are the boundaries between anxiety, depression and somatization in primary care. Mental health disorders may be “valid” but not useful in clinical practice.
