The structure of personality disorders in DSM-III

In DSM-III it is proposed that there are 11 personality disorders (PDs) that fall into 3 superordinate clusters: cluster A, labelled the odd or eccentric; cluster B, labelled the emotional, dramatic or erratic; and cluster C, described as the anxious or fearful. To check this proposal, data were obtained from a sample of 112 state hospital psychiatric inpatients via the Structured Interview for DSM-III Personality (SIDP). Various statistical techniques were applied to the data, ranging from the least constrained method of multidimensional scaling to the most constrained and statistically rigorous approach of confirmatory factor analysis. In the latter approach, the models suggested by the various statistical approaches were contrasted directly. A 3-cluster solution was accepted as the best representation of the data, although PD membership of the 3 clusters varied in some ways from those suggested by DSM-III. An exploratory correlation analysis showed that many of the items were more strongly correlated with PDs other than the ones specified by DSM-III, but generally items clustered within the 3 superordinate clusters. This issue deserves further investigation.