"Patterns of comorbidity" among DSM-III-R and ICD-10 personality disorders as observed with a new inventory for the assessment of personality disorders.

Although DSM-III-R and ICD-10 suggest the assignment of multiple personality diagnoses, a high degree of overlap may be an indicator of insufficiently distinct and too inclusive types of personality. We studied this problem with a new inventory in an unselected clinical sample. The Aachen List of Items for the Registration of Personality Disorders (AMPS) integrates the different types of disordered personality according to DSM-III-R, ICD-10, and four subaffective categories, which largely follow the typologies of Kraepelin, K. Schneider, and Kretschmer. The prevalence rate of each personality disorder was calculated in a consecutive group of 231 patients. Patterns of comorbidity were computed using odds ratios. More than one personality disorder was found in 41% according to DSM-III-R. ICD-10 showed a significantly higher degree of overlap. Interesting comorbidity patterns are discussed in comparison with several North American studies. Results indicate that clear-cut categorical personality diagnoses are not likely to be set up.