Associations between alexithymia and borderline personality criteria in personality disorders.

Alexithymia is a multifaceted construct encompassing difficulties identifying and describing feelings, limited imaginal capacity, and externally oriented thinking. Despite the high prevalence among borderline personality disorder (BPD) patients, less is known about symptom-level associations between alexithymia and BPD criteria. Prior studies highlight an elevated risk of self-injurious and suicidal behaviours associated with alexithymia. Understanding the symptom-level relationships with alexithymia may provide a more specific target for intervention. This study explored the associations between alexithymia and BPD symptom criteria in 478 psychiatric outpatients (n = 146 BPD, n = 196 other personality disorders, and n = 136 no personality disorder [PD]), assessed using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), and Structured Interview for DSM-IV Personality Disorders. BPD symptoms were dichotomized as present if scored ≥ 1 (definitely present). Alexithymia was measured using the Toronto Alexithymia Scale (TAS-20). Depression severity was assessed using the Beck Depression Inventory (BDI-II). Logistic regression was used to examine relationships between alexithymia and BPD symptom criteria in each group. In the BPD group, identity disturbance (p = .0013) was significantly related to alexithymia using the Benjamini-Hochberg Procedure for multiple comparisons. The association remained when controlling for depression severity. Among those without any PD, alexithymia was significantly associated with chronic feelings of emptiness (p = .0024) before controlling for depression. In BPD, alexithymia was most strongly associated with identity disturbance. Previous studies have linked alexithymia and identity disturbance to suicidality. This study is the first to identify an association between alexithymia and identity disturbance in BPD, underscoring impairments in the self and self-mentalizing a potential target for suicide prevention in BPD. (PsycInfo Database Record (c) 2026 APA, all rights reserved).