An Intra-Interpersonal Vulnerability Model for Understanding Trauma Conditions: Factors in the Development and Maintenance of PTSD and Complex PTSD.

Adverse childhood events and insecure attachment lead to difficulties in emotion regulation and social support, predisposing individuals to post-traumatic stress disorder (PTSD) and complex PTSD (CPTSD) when exposed to potentially traumatic events. However, the field lacks an integrated account of how these risk and protective factors combine, including the pathways through which attachment-related vulnerability contributes to trauma symptoms. This study tested a proposed intra-interpersonal vulnerability model using structural equation modelling with a sample of 706 participants (M = 30.64 years, SD = 11.00). Model fit was strong for symptoms of ICD-11 PTSD (CFI = 0.969; SRMR = 0.055) and ICD-11 CPTSD (CFI = 0.976; SRMR = 0.056). The model explained 35% of variance in PTSD symptoms and 75.7% of variance in CPTSD symptoms. Cross-validation supported the generalisability of the model, with the overall pattern of effects also replicated among participants with elevated PTSD/CPTSD symptoms. As expected, adverse childhood events were linked to attachment insecurity (e.g., β = 0.29), which influenced emotional identification, emotion dysregulation and social connectedness (β = 0.24 to β = -0.69). Contrary to expectations attachment insecurity did not impact either PTSD or CPTSD trauma symptoms directly. Emotion dysregulation was significantly associated with both PTSD and CPTSD symptoms, whereas social connectedness was associated with CPTSD but not PTSD symptoms. Overall, the results indicate that risk and protective factors build upon each other, reinforcing the importance of developmental aspects in the emergence of post-traumatic stress. Limitations include a community sample and cross-sectional data, suggesting a need for longitudinal research.