Identity disturbance in borderline personality disorder: An empirical investigation

Objective: Identity disturbance is one of the nine criteria for borderline personality disorder in DSM-IV, yet the precise nature of this disturbance has received little empirical attention. This study examines 1) the extent to which identity disturbance is a single construct, 2) the extent to which it distinguishes patients with borderline personality disorder, and 3) the role of sexual abuse in identity disturbance in patients with borderline personality disorder, Method: The authors constructed an instrument that consisted of 35 indicators of identity disturbance culled from relevant clinical and theoretical literature and asked clinicians to rate a patient on each of the items. The patient group consisted of 95 subjects diagnosed with borderline personality disorder (N=34), another personality disorder (N= 20), or no personality disorder (N=41). Relevant diagnostic, demographic, and developmental history data were also collected. The authors used factor analysis to ascertain whether identity disturbance is a unitary construct and then examined the relation between dimensions of identity disturbance and borderline diagnosis after controlling for sexual abuse history. Results: Four identity disturbance factors were identified: role absorption (in which patients tend to define themselves in terms of a single role or cause), painful incoherence (a subjective sense of lack of coherence), inconsistency (an objective incoherence in thought, feeling, and behavior), and lack of commitment (e.g., to jobs or values). All four factors, but particularly painful incoherence, distinguished patients with borderline personality disorder. Although sexual abuse was associated with some of the identity factors, particularly painful incoherence, borderline pathology contributed unique variance beyond abuse history to all four identity disturbance factors. The data also provided further evidence for an emerging empirical distinction between two borderline personality disorder types: one defined by emotional dysregulation and dysphoria, the other by histrionic characteristics. Conclusions: Identity disturbance is a multifaceted construct that distinguishes patients with borderline personality disorder from other patients. Some of its components are related to a history of sexual abuse, whereas others are not. Identity disturbance appears to be characteristic of borderline patients whether or not they have an abuse history.