1. One hundred cases of stupor were surveyed retrospectively, and investigated by follow-up methods. Only 3 per cent. were untraceable.
2. The criteria of stupor are scrutinized, and a rating scale devised to distinguish total and partial stupor and isolate them from allied states.
3. Diagnostic incidence was: depression 25 per cent.; schizophrenia 31 per cent.; mixed neurotic 10 per cent.; organic 20 per cent.; uncertain 14 per cent.
4. Demographic characteristics of the sample are discussed.
5. Constitutional factors are assessed. The evidence for a specific personality trait predisposing to stupor is unimpressive.
6. Total stupor occurred in 18 per cent. of the sample. It bears no diagnostic significance in differentiating schizophrenia from depression, but there is a suggestion that it is associated with a more favourable outcome than partial stupor.
7. In the key illness, mortality was 11 per cent. Afterwards it was 8 per cent. Mortality was most prevalent in organic cases.
8. The likelihood of recurrent attacks of stupor with schizophrenia and depression is approximately one in three.
9. Total failure to recall external events, while in the state of stupor, occurred in 31 patients. The significance of this is discussed.
10. Symptomatic outcome at time of follow-up is described, and related to the various characteristics of the sample.
11. Retrospective diagnosis was compared with follow-up assessment. Discordance in 13 cases was analysed. In only one case was depression re-classified as schizophrenia, so that the concept of Benign Stupor in depressive psychosis remains valid, and this was confirmed by a better prognosis compared with schizophrenia.
12. Stupor as an hysterical phenomenon was not encountered in isolation, being combined with either depressive or organic factors.