Living with autism or borderline personality disorder (BPD) can be challenging, but being diagnosed with both conditions together (or with one instead of the other) can be even more so, and requires further exploration of both.

"The ability to understand emotions and interact socially is impaired in both BPD and Autism." - Dr Kapil Bakshi, Consultant Psychiatrist

Here, we are looking at the main things you need to know about autism and BPD, their overlapping traits, symptoms, differences and risks, what the likelihood is that you have both, what happens if you are diagnosed with both, and what to do if you think you have been misdiagnosed with one condition instead of the other. 

At Augmentive, we aim to provide holistic, tailored mental health support to everyone so they can live their life to the fullest, so if you have questions about autism or BPD, we can help. 

What is autism? 

Autism is a neurodevelopmental condition affecting how a person interacts with other people, and how they understand and respond to sensory information around them. Autistic people can experience sensory issues that cause a negative reaction around certain triggers, which can lead to difficulties with social communication and interaction, repetitive or restricted behaviours or interests, different ways of learning or paying attention, and more. 

Some of the most common symptoms of autism experienced by adults include: 

• Difficulty reading social cues
• Difficulty participating in conversations with others 
• Difficulty relating to others’ thoughts and feelings 
• Difficulty regulating emotions 
• Difficulty building and maintaining relationships 
• Difficulty reading body language and facial expressions of others 
• Using a monotone speaking pattern, which makes it difficult to convey emotions
• Difficulty maintaining eye contact in conversations
• Restrictive or repetitive behaviours  
• Difficulty with last-minute changes to plans or routines
• Fixation on a favourite subject they care a lot about or are particularly skilled in 
• Sensitivity to sensory input like pain, touch or sound

Some of the most common symptoms of autism experienced by children include:

• Repeating certain words or phrases 
• Lining up toys or objects, and getting upset if the order is altered 
• Playing with toys in the same way every time
• Focusing intensely on parts of an object 
• Obsessively following certain routines, and becoming upset by small changes
• Obsessive interest in specific things 
• Physical movements like rocking or spinning in circles
• Unusual reactions to triggers, such as specific sounds, smells or tastes

Every autistic person will have their own unique traits and symptoms, so keep in mind that one person’s autism diagnosis can look very different to another, which is why they require bespoke support. 

What is BPD and what are the symptoms? 

Borderline personality disorder (BPD) is a type of personality disorder impacting the way an individual thinks, feels, sees the world around them, and relates to others. Research suggests BPD has around a 1.6% prevalence in the general population, and it tends to occur more often in women.  

Borderline personality disorder symptoms can include things like:

• Hypersensitivity to rejection
• Instability in relationships
• A distorted sense of self-image
• Intense mood swings
• Intense feelings of anger
• Rapid changes in interests or feelings for others
• Impulsivity or recklessness
• Avoidance of any sort of rejection 
• Self-harming behaviours
• Suicidal thoughts/behaviours

Keep in mind, not all of the above symptoms will be present in every person with borderline personality disorder, and the severity and frequency of symptoms can vary with each person. You may find more information on another type of BPD in our guide What Is "Quiet BPD" And How Can You Spot It?

What are the similarities between autism and BPD?

There are several similar traits and symptoms in those with autism and BPD which have led to research on the comorbidity of these two distinct but overlapping conditions.

Some of the main similarities noted in both autism and BPD include: 

• Emotional dysregulation: Studies have found emotional dysregulation to be a core symptom of BPD, but it is also a symptom of autism. Those with either condition may display what appear to be intense mood swings, and have difficulty regulating their emotions in daily life. 
• Difficulties with interpersonal relationships: The symptoms of both autism and BPD can lead to certain difficulties maintaining interpersonal relationships. By creating strain, these symptoms and traits can make it difficult for an individual with either condition to manage their relationships. 
• Sensitivity to rejection: Autistic people and those with BPD may experience something called Rejection Sensitive Dysphoria, which can cause an intense reaction to any sort of rejection or abandonment. This can lead to the person taking significant steps to avoid any perceived rejection. 
• An unclear self-identity: A key feature of BPD is a lack of connection to one’s self-identity, and this is also common in autistic people but for different reasons. While those with BPD may struggle with their identity due to early childhood trauma, autistic individuals who engage in ‘masking’ (taking steps to appear as neurotypical individuals) may have learned to socialise and act in a certain way by imitating others around them, which can impact their own sense of self. 
• Feelings of depression or emptiness: Masking autistic people and those with BPD both frequently report feelings of anxiety, depression and emptiness during times when they are not engaged in an activity. This is thought to be related to a lack of self-identity as described above. 
• Difficulties in social situations: In both groups, difficulties with social interactions and events are reported, which can lead to challenges creating and maintaining long-term relationships. 
• Low levels of empathy: Studies have found levels of empathy to be lower in both autistic people and those with BPD. In some autistic people, deficits in empathy are common due to an inability to recognise the feelings of others, whereas in people with BPD, this is thought to be partially due to an intense sensitivity to other people’s mental and emotional states, rather than an empathetic connection. 

What are the differences between autism and BPD?

Put simply, the main difference between autism and BPD is that BPD is a personality disorder, whereas autism is a neurodevelopmental disorder. This means the core nature of these conditions is different, but they do happen to cause some similar traits and symptoms. 

“It may help to look at the chronological history of the behaviours starting. Autism usually manifests much earlier so you start seeing symptoms at a younger age whereas BPD more commonly appears later on in around the teenage years as that is a time when our personality starts forming.” - Dr Kapil Bakshi, Consultant Psychiatrist

Some other differences in the conditions include: 

• Differences in their relationship challenges: While those with BPD tend to experience instability in their interpersonal relationships due to emotional dysregulation and a significant fear of rejection or abandonment, autistic individuals tend to struggle more with maintaining relationships due to difficulties understanding social cues and interactions, such as eye contact, nonverbal cues, and more. 
• Differences in emotional dysregulation: For autistic individuals, emotional dysregulation is more likely to come from challenges in understanding the emotions of others, whereas for those with BPD, emotional dysregulation may lead to intense mood swings or anger. 
• Differences in impulsivity: Impulsivity is common in those with BPD and in some cases can lead to self-harm actions. In autistic individuals, impulsivity often manifests in a different way, causing things like repetitive behaviours, obsessions or fixations, which serve as a way to self-soothe. 
• Differences in symptom onset: Symptoms of BPD are typically thought to begin during adolescence, while autism traits are usually present and observable in some form in early childhood.

What risks do both autistic people and those with BPD face?

In both conditions, there are a number of risk factors for co-occurring mental health conditions. These may include: 

• Eating disorders: Both those with BPD and those with autism are thought to have a higher risk of eating disorders. Some research suggests 4-23% of people with an eating disorder are also autistic, while it is thought those with borderline personality disorder also develop eating disorders as a method of gaining control. One 2020 study found a prevalence of eating disorders as high as 65.4% in patients with BPD, with anxiety and depression thought to play a key role in this. 
• Substance abuse: Issues with substance abuse are common in both groups. Autistic individuals have been found more likely to use recreational drugs to manage their mental health, while studies have found the co-occurrence rates of substance use disorders and borderline personality disorder to be up to 53.19%. Although there appears to be a link between substance abuse and autism/BPD, more research is required to establish why this is the case. 
• Victimisation: Both autistic individuals and those with BPD are at a higher risk of being victimised due to factors such as missed context cues, challenges in social reasoning, a tendency to take things literally, and more. 
• Suicide: People with a diagnosis of BPD have been found to be more prone to attempt suicide, while other studies have found those with higher autistic traits are linked to increased suicidal tendencies. 
• Self-harming behaviours: In both groups, studies say self-harming behaviours are common, although this tends to happen for different reasons. In autistic individuals this is typically done in an attempt to alleviate sensory overload, while in those with BPD, it tends to occur after an incident where attachment has been impacted. 

Can you have autism and BPD together?

Yes, a person can have both autism and borderline personality disorder, and in fact this may be more common than most people realise. According to a 2023 review of studies, around 50% of autistic subjects were thought to also meet the diagnostic criteria for at least one personality disorder. Similarly, results from a 2021 study found those with BPD had higher autistic traits than the control group, showing a clear correlation. 

In terms of prevalence of both conditions, one study found the estimated percentage of autistic people who also have BPD is thought to be 4%, suggesting it is not uncommon for BPD to coexist with autism. 

It is also thought that the coexistence of autism and BPD are more common in females, and while this remains to be confirmed, one 2023 review mentioned the findings of an older study which concluded 15% of a sample of 41 female patients with borderline personality disorder also fulfilled the criteria for autism. 

Due to the potential coexistence of BPD and autism, misdiagnosis of either condition could be a risk, which can lead to one condition or the other being left untreated. There is a significant amount of evidence to suggest a possible connection between autism and BPD, however more research is needed to confirm how the conditions are linked. 

What are the challenges involved in getting a diagnosis of both conditions?

If you or someone you love has been diagnosed with both conditions, or is seeking a diagnosis, you may be concerned about what this means for the future. It can be difficult to distinguish one condition from another in some cases, which makes diagnosis challenging. 

One of the biggest issues associated with multiple diagnoses is that one could overshadow the other in terms of treatment. As an example of this, one 2023 study details an autistic patient’s later diagnosis of BPD, which took into account symptoms such as:

• A high risk of self-injury
• Suicidal behaviours
• Impulsivity
• Emotional dysregulation
• Intense anger
• Unstable relationships
• Unstable self-image

In this case, there was concern that emphasis on BPD treatment could overlook the importance of the patient’s neurodevelopmental history, which may affect the treatment plan.

Also, having a comorbid diagnosis of autism and BPD is thought to increase the risk of suicide, according to some studies. This further stresses how crucial it is for an appropriate diagnosis to be made, and a treatment plan to be created encompassing the symptoms of both conditions. 

Have I been misdiagnosed?

Although more research is required to establish exactly how autism and BPD coexist, it is clear from the aforementioned similarities that an individual with one condition could be misdiagnosed by being told they have the other, or only one when in fact they have both. 

Due to their many similarities, studies have suggested some people may be autistic but have not been diagnosed as such, or they may be misdiagnosed with a personality disorder before they have been identified as autistic. This can pose a number of challenges. 

Further studies suggest that autism’s association with an increased prevalence of psychiatric disorders means patients may initially be referred to a mental health service for their co-occurring symptoms instead of for their autism, which can lead to key elements being missed when it comes to treatment. 

Some of the reasons an autism diagnosis may be missed include the following: 

• The psychological assessments for diagnosing autism include observations from parents and teachers, which can make diagnosis more challenging if certain symptoms are missed, or if the person evaluating is affected by bias or does not understand the symptoms. 
• Masking (the act of someone with autism presenting the outward appearance of someone who is neurotypical) can lead to misdiagnosis in autism. 
• Much of the current research on autism is focused on boys, and rarely covers autistic symptoms of other races. For this reason, diagnosis of other races and genders can be more challenging. 
• Many diagnostic tests for autism are designed for children, so adults who did not receive a diagnosis in childhood may find it challenging to obtain one in adulthood. 
• Women with autism tend to be diagnosed later than men due to their clinical presentation being less visible, and having a better ability to regulate and maintain similar social interactions to neurotypical women. 

I think I have been misdiagnosed – what should I do? 

Getting a diagnosis for BPD and/or autism can be a challenging process, but the benefits of pursuing this and ensuring you have been diagnosed accurately cannot be overstated. Misdiagnosis can cause a number of issues, as described above, so it is important to speak to a professional if you are concerned you may have these conditions and the symptoms are impacting your life in a negative way. 

Similarly, if you recognise some of the aforementioned symptoms in a loved one, you can encourage them to speak to their GP to begin the process of obtaining a diagnosis and addressing some of the symptoms causing them distress. 

You may find our guide helpful: What to expect from an adult autism assessment

If you are already working with an autism specialist, you may wish to speak to them about the possibility of comorbid borderline personality disorder, or vice versa. They may be able to offer advice on how to manage any comorbidities and where to begin with treatment. If they themselves cannot assist with the comorbid condition you believe you have, they can usually refer you to someone else who can help.  

Due to long NHS waiting lists in the UK, some people find it most helpful to reach out to a private specialist who can offer support for both conditions. At Augmentive, we believe advice and support for those with autism and/or BPD should be tailored to the individual and their symptoms, and take comorbidities seriously to ensure they are receiving the appropriate treatment. 

You may also find helpful information in our guides Is There A Link Between ADHD and BPD? and AuDHD: Dual Diagnosis of Autism & ADHD.

Whether you’re feeling off-kilter or want to shake up your routine, our state-of-the-art mental wellbeing platform gives you quick and seamless access to world-class support on your terms, from a private adult ADHD assessment to help finding an ADHD specialist near you to support you on your journey.

If you have a question about mental health, like how ADHD masking works, we’re here to assist on your journey. Our free 15 minute consultation can guide you to the most relevant specialists to answer your questions and discuss next steps.

DISCLAIMER: The content published by Augmentive is not designed to treat, diagnose, cure, or prevent any disease or condition. Always consult your GP or a qualified healthcare provider with any questions regarding a medical condition and before starting any therapy, diet, exercise, or any other health-related programme.