Psychopharmacology and the Classification of Functional Psychoses 

By Thomas A. Ban and Bertalan Pethö

Four-Dimensional Classification

Affective Psychoses

Schizophrenic Psychoses

Confusion Psychosis

The separation of confusion psychosis from confused manias dates to Wernicke (1900) who referred to confusion psychosis as "periodic maniacal autopsychosis" or "agitated confusion." A quarter of a century later the first comprehensive description of confusion psychosis was given by Kleist (1928). Consolidation of the concept is attributed to Fünfgeld (1936). He was the first to explore the possible hereditary pattern of this disorder.

 In the original formulation, confusion psychosis is a pure thinking disorder, an illness in which thinking is exclusively affected while affectivity and psychomotor activity are preserved. The thinking disorder in the excited phase of the illness is expressed as "incoherence" or in less severe cases as "incoherence of thematic choice" also referred to as "digressive thematic choice." Thus, for example, if asked to differentiate between a tree and a bush, the patient responds by describing the berry bushes at home. If asked to differentiate between giving and lending, patient responds by speaking about gifts and celebrations. Other characteristics of the excited phase are compulsive speech, intrusion of abnormal contents, misidentifications, ideas of reference and sensory (most frequently auditory) illusions.

The thinking disorder in the inhibited phase of the illness is expressed in the form of inhibited thinking associated in the more severe form with mutism and in the less severe form with impoverished speech. Other characteristics of the inhibited phase are perplexity, ideas of reference and hallucinations (auditory, visual and somatic).

Ideal – pure -- form of confusion psychosis rarely occurs. In the majority of patients, the manifestations of confusion psychosis are present in association with features of motility psychosis and/or anxiety-happiness psychosis. In the differential diagnosis mania and catatonic schizophrenia should be considered. Confusion psychosis, in the excited phase, shares with mania pressure of speech. In contradistinction to mania, however, distractibility and flight of ideas are absent, while misidentifications are frequent.

The signal difference between confusion psychosis in the inhibited phase and catatonic schizophrenia is the perplexed and anxious mood. It is present in patients with confusion psychosis, but absent in patients with stuporous catatonia.

April 10 2025