Dissociation as a Transdiagnostic Indicator of Self‐Injurious Behavior and Suicide Attempts: A Focus on Posttraumatic Stress Disorder and Borderline Personality Disorder

Dissociative symptoms and suicidality are transdiagnostic features of posttraumatic stress disorder (PTSD) and borderline personality disorder (BPD). The primary objective of this study was to examine associations between dissociation (i.e., depersonalization and derealization) and suicidality (i.e., self‐harm and suicide attempts) among individuals with PTSD and BPD. We analyzed data from the 2012–2013 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC‐III; N = 36,309). The Alcohol Use Disorder and Associated Disabilities Interview Schedule for DSM‐5 was used to assess lifetime PTSD and BPD. Estimated rates of self‐harm among individuals who endorsed dissociation were 15.5%–26.2% for those with PTSD and 13.7%–23.5% for those with BPD, and estimates of suicide attempts among individuals who endorsed dissociation were 34.5%–38.1% for those with PTSD and 28.3%–33.1% for those with BPD. Multiple logistic regressions were conducted to examine the associations between dissociation (derealization, depersonalization, and both) and both self‐harm and suicide attempts among respondents with PTSD and BPD. The results indicated that dissociation was associated with self‐harm and suicide attempts, especially among individuals with BPD, aORs = 1.39–2.66; however, this association may be driven in part by a third variable, such as other symptoms of PTSD or BPD (e.g., mood disturbance, PTSD or BPD symptom severity). These results may inform risk assessments and targeted interventions for vulnerable individuals with PTSD, BPD, or both aimed at mitigating the risk of self‐harm and suicide.