The Relationship Between Feelings of Emptiness and Self-Harm Among Thai Patients Exhibiting Borderline Personality Disorder Symptoms: The Mediating Role of the Inner Strengths

Background and Objectives: Fifty percent of individuals with borderline personality disorder (BPD) experience self-harm. One of the crucial factors related to self-harm is feelings of emptiness. While inner strengths, such as the Five Precepts, meditation, and equanimity, have been identified as potential buffers against negative mental health outcomes in BPD, their role in mediating the relationship between feelings of emptiness and self-harm is not well-documented. This study aimed to explore how these inner strengths mediate the relationship between feelings of emptiness and self-harm in individuals exhibiting BPD symptoms. Materials and Methods: A total of 302 Thai participants exhibiting BPD symptoms completed several assessments: the SCID-II Personality Disorder Questionnaire for BPD to assess feelings of emptiness and self-harm, the Inner-Strength-Based Inventory (i-SBI) to evaluate the Five Precepts, meditation, and equanimity, and the Outcome Inventory Depression (OI-Depression) to assess depression. Mean and standard deviation were used for continuous variables, such as age and OI-Depression. A t-test assessed mean differences in continuous variables between the self-harm group and the non-self-harm group. Chi-square tests examined differences in categorical variables with three or more levels, such as education. Pearson’s correlation and linear regression analyzed relationships between continuous variables, including i-SBI and OI-Depression scores. Mediation analysis was performed using IBM SPSS and AMOS, with self-harm as the outcome variable, feelings of emptiness as the predictor, and inner strengths as mediators. Results: The participants had a mean age of 36.56, with 65.4% being female. The analysis showed that the Five Precepts, meditation, and equanimity significantly mediated the relationship between feelings of emptiness and self-harm, with a standardized coefficient of β = 0.534 (95% CI = 0.417 to 0.647, p < 0.001). The indirect effect of feelings of emptiness through these inner strengths was significant (β = 0.034, 95% CI = 0.009 to 0.075, p = 0.005). The mediation model explained 38% of the variance in self-harm with a 3% increase, albeit small but significant. Conclusions: This study highlights that inner strengths negatively mediate the relationship between feelings of emptiness and self-harm, indicating that as these inner strengths increase, the direct impact of feelings of emptiness on self-harm decreases. These findings suggest that targeting inner strengths as protective factors could be a valuable strategy in developing interventions aimed at reducing self-harm by addressing the underlying emotional challenges associated with BPD.