The study was an investigation of relationships between certain psychiatric categories and personality traits. The Eysencks have argued for a dimensional relationship between the two while Foulds has argued that such a relationship should not be assumed. Also, he has proposed a hierarchical model of psychopathology where less severe pathology is subsumed under the more severe.
110 Neurotics, 98 Psychotics and 52 Non-Psychiatric controls were tested with personality and clinical inventories: the EPQ, HOQ and DSSI. Patients were allocated to psychiatric groups using the Research Diagnostic Criteria of Spitzer et al.
Examination of DSSI responses revealed a close association between DSSI diagnosis and diagnosis by psychiatric subgroup. Examination of subjects who failed to conform to Foulds hierarchy showed that the majority had acknowledged lower-level symptoms but had not endorsed them sufficiently to gain the required level of scoring.
Investigation of personality scores and the hierarchy revealed clear relationships between them, especially in the case of Eysencks factors, P and N. Postulated relationships between E, HOQ, and the categories of dysthymics and Hysterics, failed to appear.
In a Discriminant Analysis of Neurotics, Psychotics and Controls, two functions with loadings predominantly from DSSI sets emerged: Dysthymic States and Clinical Psychoticism. 83% of the sample were reallocated to their original groups on this basis.
A Factor Analysis with rotation to simple structure demonstrated closer relationships between personality and psychopathological variables. Of the five factors which emerged, two ( Neurotic ism and Clinical Psychotic ism) had major loadings from personality and psychopathological variables.
Factor Analysis of P-scale scores revealed three main factors: Affectionless Psychopathy, Paranoid Ideation and Lack of Caution. Psychotics endorsed items on the Paranoid Ideation factor more frequently than did non-psychotics. When these items were removed from the P scale, Psychotics no longer gained significantly higher scores than non-Psychotics.