Abstract
Adverse childhood experiences (ACEs) are a well-established risk factor for a wide range of mental health conditions, including personality disorder (PD). Yet, few studies have explored the relationship between ACEs and dimensional models of PD using the ICD-11 framework. The current study aimed to address this gap by establishing risk estimates and examining the potential dose-response relationship between ACEs and PD severity. A total of 918 adults with a history of mental health treatment residing in the United States or United Kingdom completed self-report questionnaires assessing ACE exposure and ICD-11 PD severity. We found a positive relationship between ACE exposure and PD severity, where greater ACE exposure was associated with an increased risk of clinically significant personality dysfunction, and this relationship occurred largely in a dose-response manner. Given that individuals with four or more ACE exposures were most at risk of clinically significant PD, these findings highlight the need to investigate potential mechanisms underlying this vulnerability and the utility of targeted interventions to mitigate risk. Moreover, the ICD-11 framework facilitated the examination of ACEs as a general risk factor relevant across PD presentations.