A distinction is often made between ‘severe and long-term mental health disorders’ (most oft en associated with schizophrenia), and ‘common mental health disorders’ (most oft en associated with anxiety and depression). Although primary care has an important role to play in the management of more severe disorders, recent policy in many healthcare systems has highlighted the role of specialist services in their management. ‘Common’ disorders are viewed as more appropriately within the remit of primary care, partly by default, as specialist services have refocused their energies, and partly by design, as primary care is seen as being able to provide appropriate, patient-centred care to this population.
Overlapping disorders may exist along a spectrum of anxiety, depression, somatization and substance misuse in primary care. Sub-threshold conditions (i.e. disorders not meeting full diagnostic criteria for mental disorders in DSM-IV or ICD-10) are prevalent and associated with significant costs and disability. 9 Th ere remains significant controversy over the nature of depression and the adequacy of different systems for classifying and describing the phenomenon and distinguishing it from other problems and disorders. Patients with long-term medical illness (particularly diabetes, coronary heart disease and stroke) have a high prevalence of major depressive illness. 12 – 15 Evidence suggests that both depressive symptoms and major depression may be associated with increased morbidity and mortality from such illnesses. 16 A useful overview of the major environmental, social and interpersonal causes of depression is given by Gilbody and Gask. 17 Higher rates of attendance and treatment for depression are associated with socially disadvantaged populations: people living in deprived areas (especially the inner city but also deprived rural areas); people who are unemployed, and living on benefits; and victims of violence, either domestic violence or living in violent areas. Depression is also associated with a lack of social support, being more common among people who are divorced or separated; single parents (usually women); widowed elderly people; non-religious communities, and communities with fewer extended families, where people are more likely to be living alone. Women consult primary care professionals much more frequently than men, who, in the age range 20–45 years, rarely consult. Depression in primary care is often viewed in terms of the stress-vulnerability model, 18 which states that destabilization (getting symptoms) is the result of long-lasting vulnerability factors (genetic risk, early life experience, physical illness and lack of social support) acting in concert with exposure to environmental stressors, usually one or more highly stressful events of which the