Overlap of autism spectrum disorder and borderline personality disorder: A systematic review and meta-analysis.
ASD and BPD co-occur at normal population rates, so shared surface behaviors are usually separate conditions, not true comorbidity.
01Research in Context
What this study did
Sorenson Duncan et al. (2021) pooled every paper they could find on autism and borderline personality disorder. They asked two simple questions: how often do the two conditions show up together, and do the symptoms really overlap?
The team ran a meta-analysis. They combined data from many studies to get one big picture of co-occurrence rates.
What they found
ASD and BPD occur together about 4% of the time. That is the same rate you would see in the general population.
In short, the overlap is no higher than chance. Shared behaviors like mood swings or social problems likely come from different brain routes, not from one combined condition.
How this fits with other research
Barnicot et al. (2026) seem to disagree at first. They found clear, large differences between autistic women and women with BPD. Sensory issues and social-cognitive quirks marked autism, while identity disruption and fast emotional swings marked BPD. The two studies actually line up: Tamara looked at everyone, Kirsten zoomed in on women and found the signals that let you tell the groups apart.
Gracia et al. (2026) add another layer. They showed that camouflaging is high in both ASD and BPD women, so surface behaviors can look the same. Their survey data extend Tamara’s warning: without deeper probes you can easily miss the real diagnosis.
Georgiades et al. (2011) foreshadowed this whole debate. They showed that emotional and behavioral problems are part of the core ASD picture in preschoolers, not extra issues. Tamara’s low co-occurrence numbers support the same idea: what looks like overlap is often ASD itself, not a second condition.
Why it matters
For BCBAs the message is simple: treat the assessment like a funnel. Start with broad screens, then add sensory, social-cognitive, and pragmatic checks. If you work with women or gender-diverse clients, add camouflaging questions. Use the profiles Kirsten found to decide which pathway explains the behavior you see. This cuts misdiagnosis and keeps your intervention laser-focused on the right skills.
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02At a glance
03Original abstract
Autism spectrum disorder (ASD) and borderline personality Disorder (BPD) share features, including social and emotion regulation difficulties. The evidence for the overlap in prevalence and clinical characteristics was systematically reviewed. Ovid Medline, PsycInfo, and PubMed were searched until November 30, 2020 using keywords relating to BPD and ASD. Studies that reported on the overlap of ASD and BPD diagnoses or traits and used a case, cohort, or case-controlled design were included. Of 1633 screened studies, 19 were included, of which 12 reported data suitable for meta-analysis. Most samples were of small, clinically ascertained groups, with 11 having high risk of bias. The pooled prevalence of BPD in ASD was 4% [95% CI 0%-9%] and of ASD in BPD, 3% [95% CI 1%-8%]. There were inconsistent findings across clinical areas. The prevalence of a dual diagnosis of BPD in ASD cohorts and of ASD in BPD cohorts was within population prevalence estimates of each disorder. Based on this data we were not able to assess whether there is misdiagnosis of one in favor of the other. Neurocognitive differences may underlie similar behavioral symptoms, but further research using larger, well-validated samples is needed. LAY SUMMARY: Autism spectrum disorder (ASD) and borderline personality disorder (BPD) have overlaps in their symptoms. The overlap in how frequently they co-occur and their presentation was systematically reviewed. We searched the key databases and including all studies that reported on the overlap of ASD and BPD diagnoses or traits and used a case, cohort or case-controlled design. Of 1633 studies, 19 were included, of which 12 reported data suitable for pooling. Most samples were of small, clinical groups, with 11 having high risk of bias. The pooled prevalence of BPD in ASD was 4% [95% CI 0%-9%] and of ASD in BPD, 3% [95% CI 1%-8%]. There were inconsistent findings across studies comparing ASD and BPD related symptoms and problems. The prevalence of a dual diagnosis of BPD in ASD cohorts and of ASD in BPD cohorts was similar to the population prevalence of each disorder. Further research using larger, well-validated samples is needed.
Autism research : official journal of the International Society for Autism Research, 2021 · doi:10.1002/aur.2619