The hierarchy model of psychiatric symptomatology: an investigation based on present state examination ratings.

Psychiatric diagnoses are arranged in a rough hierarchy, generally regarded as a convention to enable patients with a wide range of symptoms to be allocated to single diagnostic categories. Foulds, on the basis of self-report questionnaire responses, claimed that patients with symptoms at the higher levels of this hierarchy not only may but characteristically do exhibit symptoms at all lower levels as well. Foulds' hierarchy model was tested here, using PSE ratings from two large series of in-patients; at least 75% fulfilled the requirements of the model, but up to 50% of schizophrenic and manic patients failed to do so. Almost two-thirds of all patients with psychotic symptoms establishing them in one of the upper two classes of the hierarchy did not exhibit the neurotic symptoms they required lower in the hierarchy.