RESUMO
BACKGROUND: Emotion dysregulation (ED) is a core symptom of borderline personality disorder (BPD), whose aetiology has been attributed to biosocial factors. In autism spectrum condition (ASC), although ED is prevalent and is associated with decreased well-being (e.g. self-harm, suicidality), it has been understudied, especially in adults. It is therefore crucial to further understand ED in autistic adults to improve its treatment. Our study investigates ED, its behavioural correlates (e.g. self-harm, suicidality) and biosocial predictors in autistic adults relative to BPD and nonclinical controls (NC). METHODS: A total of 724 participants (ASC = 154; BPD = 111; NC = 459) completed 11 self-reported questionnaires assessing ED, ASC and BPD traits, co-occurring disorders, alexithymia, emotional vulnerability and invalidating experiences (e.g. bullying, autistic camouflaging). The occurrence of ED behavioural correlates (i.e. self-harm, history of suicide attempts, and psychiatric hospitalizations) was collected. In addition, between-groups analyses, linear regressions and machine learning (ML) models were used to identify ED predictors in each group. RESULTS: ED and its behavioural correlates were higher in ASC compared to NC, but milder than in BPD. While gender did not predict ED scores, autistic women had increased risk factors to ED, including sexual abuse and camouflaging. Interestingly, BPD traits, emotional vulnerability and alexithymia strongly predicted ED scores across the groups. Using ML models, sensory sensitivity and autistic camouflaging were associated with ED in ASC, and ADHD symptoms with ED in BPD. LIMITATIONS: ASC and BPD diagnoses were self-reported, which did not allow us to check their accuracy. Additionally, we did not explore the transactional and the moderating/mediating relationships between the different variables. Moreover, our research is cross-sectional and cannot draw conclusions regarding the direction and causality of relationships between ED and other clinical dimensions. CONCLUSIONS: ED and its behavioural correlates are heightened in BPD compared to ASC and nonclinical controls. In the ASC group, there were no gender differences in ED, despite the heightened exposure of autistic women to ED risk factors. BPD traits, emotional vulnerability, and alexithymia are core to ED regardless of diagnosis. Although less central, sensory sensitivity and autistic camouflaging seem to be specific predictors of ED in autistic adults.