High-Functioning Autism Traits in Personality Disorders: A Surprising Clinical Overlap

Living with a personality disorder can be deeply challenging, but at Philadelphia Integrative Psychiatry, Dr. Danish and his team are committed to providing nuanced, personalized mental health care. Over the years, Dr. Danish has noticed that a higher percentage of patients diagnosed with certain personality disorders—especially borderline (BPD), obsessive-compulsive (OCPD), Schizotypal Personality Disorder (STPD), and even antisocial personality disorder—also show signs of high-functioning autism spectrum disorder (ASD), often meeting full diagnostic criteria when properly assessed. These observations have led to more comprehensive evaluations, helping patients receive more targeted support and avoid misdiagnosis.

This clinical trend is gaining attention in the research world. A recent article, "The prevalence of autism spectrum disorder traits and diagnosis in adults and young people with personality disorders: A systematic review", published in the Australian & New Zealand Journal of Psychiatry, explores this very intersection. The authors examined 15 studies involving over 72,000 participants to better understand how often ASD traits and diagnoses occur in individuals already diagnosed with a personality disorder.

How Often Do Autism Traits Appear in Personality Disorders?

Significant Findings Across PD Subtypes

The review found that across different personality disorder (PD) types, there was consistent evidence of elevated autism spectrum traits and, in many cases, full ASD diagnoses:

• Borderline Personality Disorder (BPD):

• In one study of 41 women with BPD, 14.6% met full criteria for ASD following thorough evaluation.

• Another large-scale study showed an odds ratio of 10 for co-diagnosis of ASD in individuals with BPD compared to controls, although results were underpowered (p = 0.066).

• On trait measures, BPD patients scored significantly higher on the Autism Spectrum Quotient (AQ): 20.0 vs 12.9 in controls (p < 0.001), particularly in domains like social skills, communication, and attention switching.

• Obsessive-Compulsive Personality Disorder (OCPD):

• In a clinical cohort of OCD patients, 54.2% of those with comorbid OCPD were also given a clinical ASD diagnosis, compared to 18.6% of those with OCD alone (p < 0.001).

• Those with OCPD also scored significantly higher on AQ total scores: 28.0 vs 22.0 (effect size d = 0.78, p = 0.003).

• Schizotypal Personality Disorder (STPD):

• Three studies found elevated social interaction difficulties and restricted/repetitive behaviors using tools like the Autism Diagnostic Interview–Revised (ADI-R) and PANSS Autism Severity Score.

• Notably, individuals with STPD had trait scores nearly indistinguishable from those with ASD in some domains.

• Unspecified Personality Disorders:

• In a UK-based cohort, 8.2% of patients with PD received a research-confirmed ASD diagnosis, compared to 1.8% of those with mood disorders.

• A massive Danish registry study (n=5.9 million) revealed a hazard ratio of 13.7 for later ASD diagnosis among those previously diagnosed with PD. At 10-year follow-up, 1.37% had received an ASD diagnosis, notably higher than general population rates (1–2%).
  
  

Why Does This Overlap Matter Clinically?

Shared Traits and Diagnostic Challenges

Autism spectrum disorder and personality disorders share several clinical features, including:

• Emotional dysregulation

• Social interaction difficulties

• Repetitive behaviors or rigid routines

• Alexithymia (difficulty identifying emotions)

• Impulsivity or self-injurious behavior

This overlap can lead to diagnostic overshadowing, where ASD goes undiagnosed due to the more overt symptoms of PD. For instance, someone with BPD may be seen as emotionally unstable, when in fact, they also have an underlying neurodevelopmental condition that influences their interpersonal behavior.

Importantly, treatment strategies differ. Individuals with ASD benefit more from environmental adaptations and structured psychosocial interventions, whereas PDs are typically treated with long-term psychotherapy. Misdiagnosis can delay or derail effective treatment.

Implications for Practice at Philadelphia Integrative Psychiatry

These findings affirm what Dr. Danish and his team have seen in clinical practice for years. Many individuals labeled with "difficult" or "treatment-resistant" PDs may actually have underlying high-functioning ASD. Recognizing this allows for:

• Better diagnostic clarity through structured developmental assessments

• More appropriate therapy matching (e.g., DBT vs. skills-based ASD coaching)

• Reduced stigma by offering a reframed understanding of behavior
  
  

Getting in Touch with Dr. Danish and His Team

Whether you’re struggling with a personality disorder diagnosis, suspect you may have ASD, or simply want a comprehensive psychiatric evaluation, our team is here to help. At Philadelphia Integrative Psychiatry, we offer nuanced, evidence-based assessments that go beyond labels to identify the why behind symptoms. We also provide access to specialized treatment plans and cutting-edge diagnostic tools that are often unavailable in standard care.

For More on This Topic and Related Subjects, Check Out These Blogs by Dr. Danish:
https://phillyintegrative.com/blog/leucovorin-folinic-acid-and-autism-new-hope-for-improving-speech-in-children

Sources:
https://pubmed.ncbi.nlm.nih.gov/35986511/