Autistic traits and borderline personality disorder traits are positively correlated in UK and US adult men and women

Abstract

Co-occurrence of autism and borderline personality disorder (BPD) has been reported and may be more prevalent in women than men. However, the association between these conditions remains poorly understood, as does that between traits found throughout the general population. We present two studies which measured self-reported autistic traits (Autism Spectrum Quotient [AQ]) and BPD traits (McLean Screening Instrument for Borderline Personality Disorder [MSI-BPD]) in UK (N = 695) and US (N = 700) adults. As predicted, autistic and BPD traits correlated positively in both samples. However, there were no significant sex differences in the correlation strength. In the UK sample, the association between autistic traits (AQ total score) and BPD traits was no longer significant once current anxiety and depression symptoms (Hospital Anxiety and Depression Scale [HADS]) were controlled for. However, AQ subscales for Details/Patterns and Communication/Mindreading (but not Social Skills) remained significantly associated with MSI-BPD scores in the US sample. Our findings suggest that an overrepresentation of autistic women in patient populations with BPD may not be explained by traits of these conditions co-occurring to a greater degree in women than men. They also suggest that although both conditions are associated with elevated levels of anxiety and depression, BPD traits remain independently associated with specific domains of autistic traits.