(PS8-C72) Predicting Treatment Outcomes for Individuals with Comorbid Borderline Personality Disorder and Posttraumatic Stress Disorder: The Effect of Childhood Trauma

Borderline personality disorder (BPD) is a severe mental health condition that is highly complex, difficult to treat, and is often accompanied by various comorbidities (Shen et al., 2017; Tomko et al., 2014). Posttraumatic stress disorder (PTSD) is one of the most common comorbidities, with rates of PTSD reported to be between 25 to 58% of BPD cases (Barnicot & Priebe, 2013; Zanarini et al., 2004). Accordingly, a history of childhood trauma (i.e., physical, sexual, and emotional abuse) is a common experience in both BPD (Zanarini, 2000) and PTSD (Sullivan et al., 2006). However, while extant research suggests that co-occurring PTSD impairs treatment outcomes in dialectical behavior therapy (DBT; Zeifman et al., 2021), it is unclear if specific types of childhood trauma account for these effects. This study aimed to delineate 1) if BPD-PTSD individuals have poorer treatment outcomes than BPD individuals without PTSD in 12 months of DBT and 2) which specific types of childhood trauma predict poorer outcomes among those with BPD-PTSD. This study was a secondary data analysis from the FASTER trial (McMain et al., 2018) and included individuals with BPD (N = 120) receiving 12-months of standard DBT. Generalized Estimated Equations (GEE; Zeger et al., 1988) were conducted in which Childhood Physical Abuse, Sexual Abuse, and Emotional Abuse were predictors and BPD severity, PTSD severity, and total frequency of non-suicidal self-injury and suicide attempts (NSSI + SA) were outcomes. Results indicated that PTSD did not predict reduced rates of reduction in BPD severity (Wald χ²(1) = 0.74; p = 0.39), PTSD severity (Wald χ² = 1.01; p = 0.32), or NSSI + SA (Wald χ²(1) = 0.45; p = 0.50) during 12-months of DBT. Results also revealed that among those with BPD-PTSD, childhood sexual abuse did not predict reduced rates of reduction in BPD severity (Wald χ²(1) = 2.70; p = 0.10), PTSD severity (Wald χ² (1) = 2.62; p = 0.11), and NSSI + SA (Wald χ²(1) = 0.30; p = 0.59). However, exploratory analyses indicated that, among the full sample, severity of childhood sexual (Wald χ²(1) = 7.11; p = 0.008) and emotional abuse (Wald χ²(1) = 9.01; p = 0.003) predicted accelerated rates of reduction in BPD severity, while the severity of childhood physical abuse (Wald χ²(1) = 6.81; p = 0.009) predicted attenuated rates of reduction in BPD severity. As well, the severity of childhood emotional abuse (Wald χ²(1) = 4.15; p = 0.04) predicted accelerated rates of reduction in PTSD severity, while the severity of childhood physical abuse (Wald χ²(1) = 5.93; p = 0.02) predicted reduced rates of reduction in PTSD severity. Findings suggest that DBT appears to be an effective option for individuals with BPD-PTSD, while childhood emotional abuse has emerged as a critical element in predicting faster rates of recovery from BPD and PTSD.