Is It Borderline Personality Disorder or Autism?

Holly Case
3 min readJun 9, 2023
Photo by Alexandra Gorn on Unsplash

Autism is wildly under diagnosed, especially in high-functioning adults. Particularly because the more functional you are in society — or the more successfully you “mask” your autistic traits, considered “high-masking autism” — it can be very easy for you to slip between the cracks in our system.

The only issue is that high-masking autism presents many traits similar to borderline personality disorder, or BPD. How can you tell the difference?

Why autism is so underdiagnosed

Autism spectrum disorder (or ASD) is supposed to be more common in boys than in girls, which has led to many women feeling very surprised to discover in adulthood that they’re autistic.

As far as we know, 1 in 6 children are diagnosed with ASD and it’s four times more common in boys than in girls. But the way we diagnose it means that more boys are likely to be diagnosed with it than girls are. We’re so used to looking for it in boys that we often don’t recognize the symptoms of it in girls.

Symptoms of ASD in girls are likely to include the following:

  • Having unusual sensory reactions (such as finding the hems in socks uncomfortable)
  • Having passionate interests but often very few
  • Difficulty with making or keeping friends
  • Having difficulty with social communication, which tends to increase with age
  • Having difficulty with controlling emotions
  • Appearing to be shy, quiet, or unusually passive
  • Having depression or anxiety

We’re so used to looking for the symptoms of autism in boys (such as strongly preferring routines, misunderstanding social cues, or “stimming” behaviors) that we’re often missing it in girls altogether.

How is female autism like borderline personality disorder?

Even though BPD is relatively rare, four million people in the U.S. have it. In this particular instance, women are much more likely than men to get a diagnosis of borderline personality disorder.



Holly Case

Widowed young from a great man. Healing from generational trauma. Recently discovered AuDHD. Always curious and wanting to understand the world better.