Latent class analysis of deluded patients.

The internal and external construct validity of 4 severe prognostic psychopathological items is studied in deluded patients. A two-class model of latent structure analysis fits fairly well. One latent class seems to reflect a schizophrenic spectrum while the other class does not include characteristics which are known from one single nosologic entity. Thought disorder is most predictive for schizophrenic class membership, while blunted affect has the least predictive value. This 'schizophrenic' latent class has a fairly high and similar sensitivity to various definitions of schizophrenic disorder. The frequency of the types of delusions differs between the classes.