(PS2-B50) Predictors of Suicidal Ideation and Suicide Attempts in Comorbid Borderline Personality Disorder and Major Depressive Disorder

Approximately 71-83% of individuals with borderline personality disorder (BPD) have a comorbid diagnosis of major depressive disorder (MDD). Both MDD and BPD are associated with high rates of suicide, and some studies suggest this risk is further elevated in individuals with comorbid MDD and BPD. However, research is needed to identify possible risk factors that contribute towards increased suicidality in this population. Both fearlessness about death and elevated interpersonal needs are pertinent risk factors for suicidality, but they have not been specifically evaluated in individuals with comorbid MDD and BPD. In this secondary analysis of 63 females (non-MDD or BPD group: n = 20; MDD: n = 23; comorbid MDD and BPD: n = 20), we sought to evaluate whether (1) diagnosis, (2) perceived burdensomeness, (3) thwarted belongingness, and (4) fearlessness about death, significantly predict history of suicide attempts and suicidal ideation. One-way analyses of variance were conducted to evaluate group differences in perceived burdensomeness, thwarted belongingness, and fearlessness about death. Binomial logistic regressions were also performed to ascertain the effects of diagnosis, perceived burdensomeness, thwarted belongingness, and fearlessness about death on the presence of past suicide attempt or current suicidal ideation. Diagnostic groups did not significantly differ in fearlessness about death, F(2, 60) = 2.65, p = .079, but they did significantly differ in perceived burdensomeness, F(2, 60) = 19.39, p < .001, and thwarted belongingness, F(2, 60) = 34.19, p < .001. Individuals with MDD and individuals with comorbid MDD and BPD reported significantly higher perceived burdensomeness and thwarted belongingness (ps < .001) compared to the non-MDD or BPD group. Perceived burdensomeness and thwarted belongingness did not significantly differ between individuals with comorbid MDD and BPD compared to MDD alone. The binomial logistic regression predicting history of suicide attempts was statistically significant, χ²(5) = 16.09, p = .007. However, none of the predictor variables significantly predicted suicide attempts in isolation. The binomial logistic regression model predicting current suicidal ideation was statistically significant, χ²(5) = 55.57, p < .001. Perceived burdensomeness and thwarted belongingness both significantly predicted suicidal ideation in isolation (p = .027; p = .014). A 1-unit increase in perceived burdensomeness increases odds of suicidal ideation by 1.27, 95% CI [1.03, 1.57], and a 1-unit increase in thwarted belongingness increases the odds of suicidal ideation by 1.15, 95% CI [1.03, 1.29]. These findings are limited by the small sample size and cross-sectional study design. Further research is needed to clarify increased risk and predictors for suicidality in individuals with comorbid BPD and MDD to inform suicide intervention and prevention.