ANXIETY DISORDERS
Composite Diagnostic Evaluation
Thomas A. Ban, M.D.
Prelude to Nosologic Development
Nosology is the scientific discipline which deals with the identification and classification of disease. Classifying implies the “ordering of objects on the basis of their relationships” (Sokal, 1974); and a proper system of diagnostic classification provides for “denomination,” “qualification” and “prediction,” i.e., common names, descriptive features and probabilistic statements about the expected course and outcome of its diagnostic groups (Feinstein, 1972).
Development of psychiatric nosology was triggered by the work of Boisier de Sauvages (1768) who, by adopting some of the basic rules employed by Linne (1736) in the classification of flowering plants, classified "diseases as if they were specimens of nature," dividing them into 2,400 species and 295 genera. His assertion that of disease naturally occurring categories (including mental disease) exist, and can be identified in a manner which would "allow the attribution of each patient to one and only one class" by the grouping of symptoms at a particular point, or cross-section, in time, opened the path for the early syndromic classification of psychiatric disorders.
The first cross-sectional syndromic classification was that of Cullen (1769). He believed that "life is a function of nervous energy, muscle a continuation of nerve, and disease is mainly nervous disorder"; and contended that "all diseases with their seat in the nervous system are associated with and/or result in mental derangement." Introducing the term neurosis for this all-embracing (disease) category, Cullen (1772) classified medical illness into fever, cachexias, local diseases and neuroses. Recognition, however, that "not every defect of the nervous system is necessarily accompanied by a mental disorder" led to the introduction of the concept of “psychosis” by Feuchtersleben (1845) with the separation of psychiatric from neurologic disorders; and recognition that identifiable neuropathology is not present in all mental syndromes - coupled with the belief that in mental syndromes in which neuropathologic changes are absent, such changes will become detectable at a later stage of disease development - led to the re-introduction of the concept of unitary psychosis by Griesinger (1845) with the separation of sui generis psychiatric disorders from neuropsychiatric disorders.
In the ultimate analysis, it was Griesinger’s (1845) unitary concept of psychosis ( mental illness) which focused attention on the lack of identifiable neuropathology in some of the mental syndromes; and it was “unitary psychosis” from which Morel (1852) separated demence precoce (the predecessor of the diagnostic category of schizophrenic disorders), Falret (1854) separated folie circulaire (the predecessor of the diagnostic category of mood disorders), Briquet (1859) separated hysterie (the predecessor of the diagnostic category of somatization disorders), and Morel (1860) separated delire emotif (the predecessor of the diagnostic category of anxiety disorders). It was Morel’s (1860) delire emotif from which Beard (1869) separated neurasthenia (the predecessor of generalized anxiety disorder and panic disorder) and Westphal (1871-72) separated obsessive – compulsive disorder and agoraphobia (the predecessors of obsessive – compulsive disorder and phobic disorders) (Table 1).