Psychiatric Epidemiology
Conclusion: Epidemiology, Etiology, & Public Health
Epidemiology places psychiatric disorders in a broad context, which is not always apparent with individual patients. This comprehensiveness is the basis of the biopsychosocial model. Goldberg suggests a version of this model that considers three kinds of factors: those that promote vulnerability (or indeed resilience), those that “release” symptoms at a particular time, and those that determine how long a particular disorder will last. Koopman adds that there is now a shift to studying complex systems that create patterns of disease. Such studies are conducted by the comprehensive monitoring of individuals as individuals and when they interact with others and their environment.
Mental Disorder, Physical Health, & Social Functioning
A survey of the point prevalence of schizophrenia within three regions of Scotland was undertaken in 1996, replicating a similar survey conducted in 1981. In comparison to the 1981 study, the patients studied in 1996 had both more positive and negative symptoms and more nonschizophrenic symptoms. Some of the symptoms encountered involved physical health.
Religion & Mental Health
Although limited investigation has suggested an association between religion (or spiritual) health and general health (including mental health), the nature and degree of this association is not clear. Several authors have found an increase in depression among larger and generally older Protestant denominations. The specific religious creeds involved; the internalization of these creeds by the members of the organization; the psychological, social, and behavioral characteristics demanded of these beliefs; and the adherence of the believers to these demands have yet to be elucidated.
Rural-Urban Differences & the Social Drift Hypothesis
Another important finding of most epidemiologic studies is that the prevalence of some mental disorders, particularly schizophrenia, has been found to be higher in urban and industrialized areas than in rural areas. A number of explanations for this finding have been suggested: social migration (the downward drift of persons and families experiencing schizophrenia to lower socioeconomic levels), inbreeding among the mentally ill, and the greater availability in urban areas of services for the chronically mentally ill. These differences may also reflect the comparative integration and stability of rural areas. Leighton and colleagues, in their study of rural Nova Scotia, found that depression (and other psychiatric disorders) were more common for all ages in “disintegrated” communities. Given the recent emphasis on the genetic basis of many psychiatric disorders, more research must be done on the degree of possible inheritance of these disorders in populations, and on the social drift hypothesis, before firm conclusions can be reached.
The Biopsychosocial Model & the Web of Causation
The late George Engel promulgated a theoretical model, based on general systems theory, of the etiology of mental disease. Research had demonstrated, and indeed continues to demonstrate, that unitary explanations are not adequate to explain disease etiology or thus indicate appropriate prevention and treatment strategies. Engel suggested an interrelatedness among biological, psychological, and social factors. Biological factors included anatomic and molecular factors and those factors related to gender, age, ethnicity, and genetics. Psychological factors related to the individual’s personality. According to Engel’s theory, social factors included family, society, culture, and environment; other authors would include religious and spiritual as well as economic factors in this group. Engel also believed that the physician’s contribution, through a psychosocial presence, to this “collaborative pathway to health” was often inseparable from that brought by the patient.
Historical Perspective
First-Generation Studies
The earliest formal first part of the 20th century. They were generally of limited scale, relied on institutional records, and used small groups of informants for their data. These were “convenience” studies in which, instead of initiating the surveys themselves, epidemiologists assembled health data from those persons who had already received treatment for a medical problem or had committed suicide. A notable exception was Brugger’s study in Thuringia, in which he attempted to use census tracts to identify mental illness in a defined population. Ferris and Dunham’s relatively large pre–World War II study examined the geographic distribution of patients with mental disorders in mental hospitals in the Chicago area. They found that manic-depressive illness was distributed equally throughout the geographic area, whereas schizophrenia clustered in the lower socioeconomic areas.