Pseudodementia: facts and figures.

The historical and conceptual aspects of the pseudodementia state are briefly touched upon. A "collective sample", composed of 61 cases culled from the literature, is analysed and compared with the "Fulbourn sample" consisting of 22 cases reported for the first time. Two sub-types of pseudodementia emerge, one associated with depressive illness and the other with delirium. A follow-up of the Fulbourn sample (1-4 years after discharge) showed 14 patients to be alive and 8 to show no signs of dementia. No variable except the diagnosis "non-specific psychosis" correlated with death during the follow-up period.