Possible drivers of self-harm severity - relative contributions of post-traumatic stress and levels of personality functioning – results from the Extreme Challenges project

Background: Self-harm (SH) is common, but its severity varies. Severe cases may involve extensive hospitalization and high suicide risk. Although SH is associated with post-traumatic stress disorder (PTSD), personality disorder (PD), and complex cases of PD-PTSD comorbidity, factors related to SH severity are sparsely researched. Aims: The study aims to investigate how SH severity relates to PTSD symptoms and different domains of personality functioning. The study also aims to explore indirect associations of interpersonal functioning, PTSD symptoms and SH severity. Methods: = 403, period 2019-2022). Patient self-reports included current (last 6 months) SH and suicide attempts, PTSD symptoms, and self and interpersonal domains of personality functioning. Results: More severe PTSD symptoms and poorer self-functioning (self-control and identity integration) were significantly and independently associated with greater SH severity. The association between PTSD symptoms and increasing SH severity was partially mediated by greater impairment of self-control and identity integration. Interpersonal domains were not associated with SH severity. Conclusion: This study highlights post-traumatic stress and personality problems as common clusters of symptoms among patients with increasingly severe SH. Further exploration indicated personality functioning self-domains as potential drivers of the association between post-traumatic symptoms and SH severity. Results support integrated, individualized treatment addressing SH in light of both trauma burden and personality functioning.