(PS8-21) Acute Effects of Inpatient Brief Cognitive-behavioral Therapy for Suicide Prevention on Non-suicidal Self-injury: Exploring the Role of Improved Distress Tolerance

Abstract Text: Non-suicidal self-injury (NSSI), defined as deliberate harm to one’s bodily tissue without intent to die (e.g., cutting, burning), is common in individuals who attempt suicide. Moreover, NSSI is a known risk factor for future suicide attempts. Thus, it is important to identify effective treatments for NSSI and related mechanisms when working with a suicidal population. The present study is a secondary analysis of a randomized clinical trial comparing inpatient treatment as usual (TAU) to TAU plus Brief Cognitive-Behavioral Therapy for Suicide Prevention (BCBT-I). BCBT-I teaches skills for crisis management, maintaining safety, and emotion regulation. Distress tolerance is an important dimension of emotion regulation, and it is also a trait that is strongly associated with NSSI. This relationship may suggest that improving distress tolerance throughout treatment could reduce NSSI. The proportion of participants who engaged in NSSI during their inpatient stay was determined. It was hypothesized that there would be fewer participants in the BCBT-I versus TAU group that would engage in NSSI during their inpatient stay. It was further hypothesized that there would be a group by time interaction for improvement in distress tolerance, such that participants in the BCBT-I versus TAU group would demonstrate more significant improvement in distress tolerance during their inpatient stay. The relationship between improvements in distress tolerance and occurrence of NSSI was also explored. Two hundred participants with history of suicide attempt were enrolled (52% female gender identity, 10% gender diverse, 25% Hispanic, 34% people of color), and of these 188 (BCBT-I n = 90; TAU n = 98) completed the Columbia Suicide Severity Rating Scale (C-SSRS) at discharge. In addition, a subset of participants (BCBT-I n = 47, TAU n = 49) completed the Distress Tolerance Scale (DTS; added to the study protocol about midway through enrollment) at study intake and discharge. A chi-square analysis indicated that significantly fewer BCBT-I (n = 5, 5.6%) than TAU (n = 14; 14.3%) participants engaged in NSSI during their inpatient stay [χ2 (1) = 3.94, p = .047]. Further, analysis of variance of DTS total scores demonstrated a statistically significant group (BCBT-I versus TAU) by time (intake versus discharge) interaction [F (1) = 5.43, p = .022], with larger improvements in distress tolerance occurring in the BCBT-I (intake M=2.44; discharge M=2.71) than TAU (intake M=2.54; discharge M=2.41) group. Further, change in DTS scores from intake to discharge was significantly associated with occurrence of NSSI (r = -.344, p < .001), such that improvement in distress tolerance was associated with absence of NSSI. These results provide additional support for the efficacy of BCBT-I to reduce self-harm behaviors and suggest improved distress tolerance as a potential treatment mechanism. The results also highlight the importance of providing inpatients with cognitive-behavioral interventions like BCBT-I, as the acute effects on NSSI appear to be beneficial. It will be important for future research to determine the causal relationship between change in distress tolerance and engagement in NSSI over the course of treatment.