Review of the literature in regard to the organic hypotheses has brought out certain fundamental observations. 1.That even in the various forms of `organic' states, the incidence of depersonalization phenomena is on the whole fairly constant, 25 per cent to 50 per cent, except in cases of more gross chronic organic psychosis where the evidence is rather lower. 2. This observed evidence is very similar to that found in studies involving `normal' populations. 3. There are a number of studies which have failed to demonstrate any quantitative relationship between the degree of torpor and the development of depersonalization. 4. Detailed studies on the performance of depersonalized subjects on psychometric tests have produced little evidence to substantiate a specific relationship between clouding of consciousness and depersonalization. 5. There appears to be a large population of individuals who never suffer from depersonalization under any circumstances.
These facts seem to indicate: (a) that there may well be a ` built in' or `preformed' mechanism in approximately 40 per cent of the population to exhibit depersonalization; (b) that the factors which initiate such a response are not specifically those associated with clouding of consciousness; or (c) where clouding of consciousness appears to be playing a part it may well be the presence of another common factor that is more relevant.
Recent work on the relationship between depersonalization and the affective state of the subject has strengthened the view that there is a special connection between depersonalization and depressive mood change. The importance of the role of anxiety in depersonalization is not fully resolved at the present time. Suggestions that depersonalization is a variety of `body image' disturbance or a variety of schizophrenia appear to be refuted. Psychoanalytic views of depersonalization appear to have altered but little from the past and do not appear to add much to our understanding of either the content or the form of the experience.