Prevalence of Personality Disorders at Midlife in a Community Sample: Disorders and Symptoms Reflected in Interview, Self, and Informant Reports.

This report is concerned with the prevalence of symptoms of specific personality disorders in a representative community sample and draws attention to the importance of different sources of diagnostic information. We recruited a sample of 1,630 people between the ages of 55 and 64 to participate in a study regarding personality and health. Using careful recruitment methods, our participation rate was 43 %. Participants completed the SIDP-IV interview as well as a questionnaire (self-report MAPP). Informants completed the same questionnaire (informant MAPP), describing the participant's maladaptive personality characteristics. According to the diagnostic interview, 7 % of participants met criteria for exactly one PD, 1 % met criteria for 2 or 3 PDs, and 2 % met criteria for PD NOS (defined as 10 or more miscellaneous criteria). Avoidant and obsessive compulsive PDs were the most common types. Correlations between the three sources of information indicated significant agreement among these measurement methods, but they are not redundant. In comparison to interview and self-report data, informants reported more symptoms of personality pathology (except for avoidant PD). Symptoms of personality pathology are continuously distributed, and subthreshold features may have an important impact on health and social adjustment. In this community sample, rates of co-morbidity among PDs and the proportion of PDNOS diagnoses are substantially lower than reported from clinical samples. Future research must evaluate the validity of diagnostic thresholds and competing sources of diagnostic information in relation to important life outcomes.