The Association Between Identity Functioning and Personality Pathology in Female Patients with Eating Disorders

In the present study, we investigated the associations between the three identity dimensions of Kaufman (Consolidated Identity, Disturbed Identity, Lack of Identity) and symptoms of personality disorders (PDs) in 176 female inpatients with an eating disorder (ED). We examined five aspects: the prevalence of categorical PD diagnoses in patients with EDs; the relationship between dimensional PD scores and identity dimensions as well as their relationships with age and ED subtype; and the unique variance in dimensional PD scores explained by identity dimensions, while controlling for age and ED subtype.

To assess identity functioning, we made use of the Self-Concept and Identity Measure, and to assess PDs, we used the categorical and dimensional scores of the Assessment of DSM-IV Personality Disorders.

The findings showed that the avoidant, obsessive-compulsive, and borderline categorical PDs were the most frequently reported PDs. Age was negatively related to all Cluster B PDs and Disturbed Identity, and binge-eating/purging ED patients reported significantly more Cluster B PD features compared to restrictive ED patients. ED subtype and identity dimensions were unrelated. Correlational analysis showed that all dimensional PD scores were positively related to Disturbed Identity and Lack of Identity and negatively related to Consolidated Identity. The results of the hierarchical regression analyses showed that Cluster A PDs were significantly predicted by Lack of Identity, controlled for age and ED subtype. Additionally, Cluster B PDs were significantly predicted by Disturbed Identity. Finally, two of the three cluster C PDs were predicted by Lack of Identity (avoidant and obsessive-compulsive PD), whereas the dependent PD was explained by Disturbed Identity.

The co-occurrence of identity issues in both PDs and EDs underscores the role of identity as a transdiagnostic feature. Accordingly, using identity-based interventions in treatment may have broad therapeutic benefits across these disorders.