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.