Ego disturbances in the sense of Kurt Schneider: historical and phenomenological aspects.

The phenomena which were grouped together by Kurt Schneider to constitute the ego disturbances have always been of particular diagnostic relevance for schizophrenia. The manner in which these symptoms are described and distinguished from other psychopathological symptoms has generally been rather imprecise. The introduction of phenomenological methods into the field of psychiatry led to considerable improvements in symptom descriptions and to a clearer distinction between psychotic and nonpsychotic experience. Continued developments in phenomenology have further incorporated aspects of schizophrenic symptom development and in doing so have brought so-called transitional phenomena and the core schizophrenic syndrome into focus. The ego disturbances accordingly appear to stem from a particular form of depersonalization which is described as a modified sense of mineness and which can be distinguished from the neurotic experience of depersonalization.

The phenomenological stability of depersonalization: comparing the old with the new.

The view that depersonalization is a stable syndrome became well established during the first half of the 20th century. Current operational definitions restrict depersonalization to the experience of unreality. This is likely to neglect clinical features of potential neurobiological relevance. By using the year 1946 as the dividing line, 200 cases of depersonalization disorder reported in the medical literature since 1898 were divided into two historical groups (1 and 2). The groups were then compared in terms of 18 phenomenological variables with a sample of 45 prospective cases of DSM-IV depersonalization disorder (group 3 or gold standard). Groups 1 and 2 differed in terms of their symptom profile, but the highest frequency that symptoms achieved in either group did not differ from the rates identified in group 3. A core of (invariable) symptoms, including emotional numbing, visual derealization, and altered body experience, was present throughout. These high rates of spontaneous reporting in all three groups may be explained by the fact that they all are accompanied by specific distress. With the exception of heightened self-observation and altered time experiencing, all other symptoms were significantly lower in group 2. The results suggest that the phenomenology of depersonalization has remained stable over the last 100 years. Our study found differences in frequency for some symptoms, but these are likely to have resulted from reporting biases, themselves governed by changing theoretical views. Clinical descriptions became poorer as the present is approached. This cannot be solely explained on the basis of empirical progress, and it is likely that theoretical biases also play a role. Because the neurobiological relevance of the symptoms of depersonalization remains unknown, it makes sense to continue collecting as many symptoms as possible, thereby avoiding both biased selection or premature closure.

Depersonalization: a conceptual history.

As with other clinical phenomena, the historical analysis of the term, concepts and behaviours involved in the construction of 'depersonalization' should provide researchers with an essential frame for its empirical study. Before the term was coined in 1898, and under a variety of names, behaviours typical of 'depersonalization' were reported by Esquirol, Zeller, Billod, and Griesinger. The word 'depersonnalisation, derived from a usage in Amiel's Journal intime, was first used in a technical sense by Ludovic Dugas. The new disorder has since been explained as resulting from pathological changes in the sensory system, memory, affect, body image and self-experience. During the 1930s, evolutionary views became popular, particularly in the work of Mayer-Gross. The unclear conceptual boundaries of depersonalization still invite confusion and often enough fragments of what used to be its core-behaviour are used to diagnose the disorder. Depersonalization has of late become subsumed under the dissociative disorders. The definitional instability of the latter, however, has caused further complications to the study of depersonalization. It is recommended that the term is used to refer only to the original core-behaviour as this has shown adequate stability.

Descartes, consciousness and depersonalization: viewing the history of philosophy from a Strausian perspective.

This paper develops particular Strausian -like themes on the formation and structure of the Cartesian problematic. Particularly, my interest is to link the Cartesian 'invention' of consciousness (or 'the mental') in the philosophy of mind with the issues of representation and 'the problem of the external world' in epistemology. The Cartesian novelty becomes clear by comparing Cartesian scepticism with Greek classical scepticism . I end with some speculative clinical (i.e., psychiatric) suggestions on possible roots of the Cartesian invention.