MULTIPLE AXIS-II DIAGNOSES OF PERSONALITY-DISORDER

Background. Simultaneous diagnosis of more than one personality disord er (PD) has been termed 'comorbidity' or 'co-occurrence' implying that single diagnoses are the norm and multiple diagnoses interesting exce ptions. Surveys of PD subjects in fact show 1.5-5.6 diagnoses per subj ect. Our study explores the hypothesis that multiple PD diagnosis is c ommon and increases with increasingly personality disordered populatio ns. Method. The PDQ-R questionnaire was administered to three UK sampl es: referrals for specialist PD in-patient treatment (n = 275); high t ariff offenders attending a probation centre (n = 57); and undergradua te students (n = 274). Results. Means of 6.0 (95% CI 5.7-6.3), 4.0 (3. 1-5.0) and 3.4 (3.0-3.8) PDQ-R diagnoses per subject were found respec tively. High rates of PD diagnosis in individual subjects suggest that multiple diagnosis is the norm rather than the exception. Conclusions . Multiple diagnosis of PD is better construed as 'breadth' of psychop athology rather than comorbidity and is a function of sampling frame. High rates of multiple diagnoses question the interpretation of studie s of any single PD. The graded construct of 'breadth' of axis-ii patho logy may further our understanding of PD.