Psychopharmacology and the Classification of Functional Psychoses
By Thomas A. Ban and Bertalan Pethö
Four-Dimensional Classification
Psychosis: Organic vs Functional
Acute Exogenous Predilectional Types
Conceptual separation of organic from functional psychoses provided the necessary end-point for Bonhoeffer (1909) to develop his concept of "acute exogenous psychoses," i.e., psychoses associated with and/or the result of systemic disease. Within Bonhoeffer's frame of reference "exogenous psychoses" are non-specific secondary manifestations of systemic disease and as such distinct from sui generis psychiatric disorders.
Bonhoeffer's concept of "exogenous predilectional types" is based on the recognition that psychotic reactions associated with systemic disease appear in one of four forms, i.e., delirium (which may occasionally be disguised with hallucinosis as the dominant clinical feature), epileptiform reactions (which may present as states of anxious or frenzied motor excitement, or alternatively as quiet, affectless twilight states), stupor and confusional states (which may show hallucinatory, catatonic, or dissociative features). Since similar reactions may occur in association with different illnesses, and the course of illness is not determined by the presenting clinical picture, but by the patient's general constitution and the severity and duration of the underlying physical disease, Bonhoeffer maintained that the prevailing psychopathological syndrome reflects a specific predisposition which does not provide interpretable clues for an etiological understanding of the disease.
Bonhoeffer's concept of "acute exogenous psychoses" is subsumed under the heading of "symptomatic psychoses" in the British literature. The typical obligatory feature of these psychoses is disturbance of consciousness. The altered state of consciousness varies in degree from the swimming head of the common cold to the loss of consciousness in the coma of enteric fever or septicemia. It may be seen in a severe form in the delirium accompanying acute disease. In the psychoses caused by subacute and chronic illness, consciousness is less clouded or may even be clear. This disorder has been differentiated from delirium and termed confusional state. It is also referred to as amentia in German psychiatry and as subacute delirious state in British psychiatry (Mayer-Gross, Slater and Roth, 1960). Other, atypical-facultative manifestations of exogenous psychoses are dependent on a general or a specific predisposition. The development of a transient catatonic, hyperthymic, dysthymic or amnestic syndrome is attributed to a general predisposition, while the development of a transient schizophreniform, paranoid, or hallucinatory reaction is attributed to a special predisposition. The resultant "atypical forms" with full recovery (reversibility) were referred to as "transient organic syndromes" (Durchgangsyndrome) by Wieck (1956, 1957). All these different typical and atypical forms of disease may terminate in full recovery, or yield to organic neurasthenia (also referred to as irritable debility or emotional hyperesthesia), Korsakoff's amnestic syndrome or generalized dementia (Nyiro, 1962). These latter manifestations provide for the link between the acute exogenous (symptomatic) psychoses with prevailing delirium and the subacute and the chronic exogenous (organic) psychoses with prevailing dysmnesia and dementia respectively (Table III).