Purpose: According to DSM, interpersonal functioning deficits are a main criterion for the general definition of personality disorders (PDs), but some PD diagnoses do not appear to be related to impaired interpersonal functioning. Social deficits have rarely been studied in all PD dimensions to date.
Methods: We analyzed 511 adults aged 20-41 years from the general population of the canton of Zurich, Switzerland, using data from the Epidemiology Survey of the Zurich Programme for Sustainable Development of Mental Health Services (ZInEP). PD dimensions were measured with a questionnaire and indicators of interpersonal functioning with a semi-structured interview. Associations were analyzed with generalized linear models.
Results: All PD dimensions were significantly associated with various indicators of interpersonal functioning deficits, such as distress and conflicts in friendships and partnership, feeling lonely, few close friends, and reduced social support. Schizotypal and borderline PD were relatively strongly associated with distress in friendships when compared with other PD dimensions. Furthermore, both dimensions were significantly related to all indicators of interpersonal functioning deficits.
Conclusions: Subjects scoring high on any PD dimension reported considerable deficits in interpersonal functioning as characterized by a solitary lifestyle, conflictual and distressful social relations, and lack of social support. All DSM-IV PDs are associated with poor interpersonal functioning, but there is some evidence that schizotypal and borderline symptomatology affects deficits in social interactions even more profoundly and pervasively than other PD dimensions.