Women with autism and those with borderline personality disorder share certain emotional difficulties, but a new study suggests the two conditions are far more distinct than clinicians have long assumed. The research, published in the journal Autism, could help reduce the misdiagnosis rates that have left many autistic women waiting years for an accurate diagnosis.
Borderline personality disorder, known as BPD, is one of the most common diagnoses given to people before they receive an autism diagnosis. Autistic women in particular are frequently misdiagnosed with BPD, partly because both conditions can involve emotional sensitivity and difficulties in social situations. Researchers at City St George’s, University of London, along with colleagues from University College London and the University of Oxford, set out to map the similarities and differences more precisely.
The team recruited 51 women or people assigned female at birth with a confirmed autism diagnosis, and 51 with a confirmed BPD diagnosis. Participants completed a series of self-report questionnaires covering emotional regulation, sensory sensitivity, social behaviour, identity, and experiences of being alone. Screening measures were used to ensure that neither group met full diagnostic criteria for the other condition, though individuals with subclinical traits were included.
The findings revealed that autistic participants scored substantially higher on measures of sensory processing, social camouflaging, and preference for routine. Social camouflaging, sometimes called masking, refers to the effort autistic people make to conceal their natural traits in social settings. These differences were among the most pronounced in the entire study, suggesting that sensory sensitivity and masking behaviour may be among the clearest markers distinguishing autism from BPD.
Those with a BPD diagnosis, by contrast, showed markedly greater difficulties with identity, impulsivity, and distress when alone. Identity disruption, described as a fragmented or unstable sense of self, emerged as the single biggest difference between the two groups. Emotional reactivity and difficulties regulating emotions were also significantly more pronounced in the BPD group, contrary to the researchers’ initial expectation that these traits would look similar across both diagnoses.
A combination of five measures, covering social cognition, social camouflaging, identity difficulties, impulsivity, and coping with being alone, correctly classified 95% of participants. The researchers noted, however, that when scores from both groups were compared against general population norms, autistic women still showed more BPD-aligned traits than the average person, and vice versa. The differences were real, but they existed along a continuum rather than as a clean divide.
The study’s authors suggest that adding targeted questionnaires on sensory processing, repetitive behaviour, and identity to clinical assessments could improve diagnostic accuracy for women being evaluated for autism or BPD. Given that women with autism are known to be diagnosed later in life and are more likely to be given a psychiatric diagnosis first, clearer clinical tools could have a meaningful impact on thousands of people’s lives.