Psychopharmacology and the Classification of Functional Psychoses
By Thomas A. Ban and Bertalan Pethö
Four-Dimensional Classification
Psychosis: Organic vs Functional
Chronic (Generalized) Dementias
The recognition that the continuous presence of traumatic biological factors may result in dementia threw light on Bayle's (1822, 1825, 1826) thesis that persistence of arachnitis (during the third and final stage of its development) yields to dementia in patients. It also brought to attention some of the early contributions of Pinel (1801). In his classification of psychiatric disorders, he was the first to employ the term "dementia" to describe illnesses which lead to intellectual deterioration. It should be noted, however, that the crucial distinction between "inborn idiocy" and "acquired dementia" was made by Esquirol (1839) almost 40 years later.
It was the early 19th century French school of psychiatry which had delineated the essential psychopathological features that result from persistent (chronic) brain damage. However, the findings of the French school became meaningfully interpretable only after the delineation of the essential psychopathological features of acute biological trauma by the early 20th century German school. Integration of the contributions of the two schools yields the still prevalent position that delirium, dysmnesia and dementia indicate the presence of somatic factors in the etiology of psychotic disease with a high level of probability.
The three "Ds" provide the necessary clues for the separation of organic psychoses with psychopathological manifestations prevailingly in the connecting functions (such as consciousness, memory and personality) from the functional psychoses with psychopathological manifestations prevailingly in the perceptual-cognitive, relational-affective and motor-adaptive functions (such as perception, thoughts, emotions, mood and motor behavior). Identification of the differential psychopathological structures involved in organic and functional psychopathologies and recognition of the relationship between specific brain structures and the sites of psychopathology has raised the possibility that in case of non-specific organic psychopathology the primary impairment responsible for the psychopathological changes is in the reticular formation and temporal lobe structures intrinsically linked with connecting functions.
On the other hand, in case of specific functional psychopathology the primary impairment responsible for the psycho- pathological changes might be in limbic lobe structures in general and in frontal, parietal, temporal and/or occipital structures in particular, intrinsically linked with relational-affective, motor-adaptive and perceptual-cognitive functioning (Table IV).