Borderline Personality Disorder (BPD) is one of the 11 Personality Disorder conditions in the USA DSM 5 TR. Medically speaking, a person who meets at least 5 of the 9 criteria listed for BPD matches this condition. Statistically, BPD diagnosis unfairly biases towards women (around 80% women to 20% men). BPD is stigmatised by the health industry because it is considered to be highly resistant to medication and psychological therapies, and I argue that this is because it is frequently the wrong diagnosis.

We will first look at the medical model for BPD, then move on to some arguments about why it is not a good diagnosis, and is often the wrong diagnosis.

Medical Definition of BPD

BPD is diagnosed via the criteria for the DSM 5 TR (USA), and ICD 11 (most of the world). For the ICD, you first need to qualify for a Personality Disorder before you qualify for the Pattern of Borderline.

BPD has received a great deal of stigma, so there have been various efforts to re-brand the diagnosis in order to decrease the stigma. This hasn’t worked, and it has corrupted a genuine other psychiatric label.

These are all considered to be the same condition in mental health circles:

• BPD – Borderline Personality Disorder
• EUPD – Emotionally Unstable Personality Disorder
• cPTSD – complex Post Traumatic Stress Disorder

Personality disorders are a weird category in mental health, so let us first understand those.

Understanding Personality Disorders

PD History

The Personality Disorder category in mental health is a holdover from the dark times of psychiatry that just refuses to die.

 “Science advances one funeral at a time”, attributed to Max Planck

Not long after mental health was torn away from the idea that insanity was the work of the devil, poor mental health was attributed to moral issues aka victim blaming. Moral issues implied an inherent flaw in a person’s persona or desires. This evolved through Moral Insanity, the medicalised version of a flaw in your morals, through Disorders of Character and finally to Personality Disorders. What does this mean? It means that you are odd and the diagnostician isn’t sure why.

There are 11 personality disorders to try to put your particular set of quirky traits into, based on which diagnostic criteria you meet better and which category the diagnostician thinks better describes you. While each has a set of diagnostic criteria to guide the diagnostician, the high flexibility of interpretation in the criteria allow the diagnostician to categorise pretty much anyone who is struggling to any of the Personality Disorders. It is almost like Astrology.

However, if you are trained to recognise Autism and ADHD, reading through the diagnostic criteria for Personality Disorders shows that that 10 of the 11 are essentially describing someone who shows strong traits of Autism and or ADHD. This can leave one wondering why the diagnostician diagnosed a PD instead of Autism and or ADHD, and the unfortunate answer is generally because the diagnostician was not educated in Autism and ADHD. By default, the standard education given to psychiatrists, general doctors and therapists does not include Autism and ADHD education.

“If all you have is a hammer, everything looks like a nail”, attributed to Abraham Maslow

PD, Neurodevelopmental Disorder and AuDHD

Personality Disorder, as a category, evolved in parallel to Autism (1911 was the first diagnosis, 1970 was the modernisation of the concept), and the ADHD (1779 was the first medical description, 1960 was the first successful medication treatment and thus the modernisation of the concepts). What that means is that the some schools of therapy taught Autism, some taught ADHD and most taught Personality Disorders. In my opinion, they were all describing the same elephant in the dark, but since they didn’t compare notes, they mostly thought it was 3 different beasts. ADHD medication is very effective for all 3, Autism social therapies and mood management therapies are excellent for all 3.

More researchers are coming around to my conclusion about BPD being neurodevelopmental, but very few have yet to conclude that it is essentially AuDHD (both Autism and ADHD).

DSM 5 TR Diagnostic Criteria

The DSM does not require a person to meet the criteria for Personality Disorder first, they only need to meet the criteria for Borderline Personality Disorder. DSM is from the USA and is often very Western Culture centric.

ICD-11 Diagnostic Criteria

The ICD is the International Classification of Disease by the World Health Organisation (WHO). It is more culturally diverse and is supposed to be the default standard here in Western Australia, although most practitioners default to the DSM instead.

BPD Aetiology

Aetiology (Etiology for USA) is looking for the cause of disease or disorders.

The most often cited cause for BPD is trauma, genetic predisposition / neurobiological and environmental factors are cited.

I have doubts that BPD is a thing in and of itself, rather than a diagnosis given by people who don’t have the right qualifications to recognise Autism and ADHD. Trying to work out what causes a thing that is not real falls into the Begging the Question Logical Fallacy, where you assume a thing is true and then try to explain it. If it is false, then there is no aetiology.

However, since we are looking at the existing Medical Model, we will look at what the current aetiology for BPD is.

Trauma Aetiology Hypothesis

The trauma aetiology hypothesis has led to the idea that perhaps BPD is a complex form of PTSD, which has led to many practitioner preferring to call BPD cPTSD. While now commonly practiced, in my professional opinion, this is wrong.

PTSD stands for Post Traumatic Stress Disorder, and describes the disorder you get where post (after) a trauma event, you are struggling due to distress around that ordeal. It is one of the few psychiatric conditions that actually describes itself well. PTSD is characterised by nightmare dreams, flash backs (waking dreams) and trigger sensitivity (that are connected to the trauma event). PTSD people are often feeling very stuck in fight / flight mode all of the time, or very quick to heightened arousal (switching from semi-relaxed to fight / flight for no good reason) – this is only since the trauma event.

The problem with the trauma aetiology hypothesis is the low co-occurrence of BPD and trauma. While people diagnosed with BPD do have a higher correlation of diagnosable trauma (between 50-65% depending on the study, eg childhood physical abuse), there is still a large number of people diagnosed with BPD who do not have any trauma history. When I spoke to a BPD expert (at the time considered to be the top expert in Australia) about how we explain BPD in the 35-50% of people without a trauma history, she informed me “we just haven’t figured out what their trauma is yet”. That isn’t how science or trauma work.

“It doesn’t matter how beautiful your theory [hypothesis] is, it doesn’t matter how smart you are. If it doesn’t agree with experiment, it’s wrong.” – Richard P. Feynman

Prior to the attempt to co-opt cPTSD into the rebadging of BPD, Complex Post Traumatic Stress Disorder meant a version of PTSD that did not respond positively to regular PTSD treatment, generally due to a co-occurring condition or situation. Now cPTSD has become synonymous with BPD.

Genetics

There are two major aetiologically hypotheses here.

1. Genetic predisposition
2. Neurodivergent

Genetic predisposition indicates that some people have a likelihood of developing BPD traits due to some level of inheritance, but the behaviours and experience do not develop unless an environmental situation triggers the traits. This idea is often cited to explain why some people (more than one) in a family have a particular trait and some people don’t – and that trait develops later in life. This falls back on the idea that trauma or substance misuse can trigger the condition. I give this low credence – the genetic predisposition is always a weak explanation for why someone becomes different to expectations at some random point in their life; that is, it implies an explanation without giving any real details.

Neurodivergent is a term that has been coined around 1990 to explain that conditions like Autism and ADHD are more about neurological differences than broken brains. While the medical model has been slow to catch up to what this implies, continuing to insist that Autism and ADHD are both inherently disabilities first and differences second, Neurodivergence is a powerful concept to help us understand that some people have different types of brains, and thus different ways of being. Neurodivergence refers to how brains can differ, Neurotypical means the largest and most common type of brain, and Neurodivergent refers to being different than that typical brain type. Autism is a group of Neurodivergent brains, with Neurodivergence within that grouping, and the brains inside the grouping are more similar to each other than they are to Neurotypical brains.

Generally, Neurodivergence means that you are born with the neurological differences. There are some specific types of acquired brain injuries or organic brain damage that can lead to different brain processes such that your brain may no longer work in the typical way – that is, your brain has diverged from Neurotypical. Some old studies have suggested that prolonged trauma can lead to neurological differences, which may explain neurodivergence. These studies are questionable in conclusion and very hard to replicate to see if they are true. The questionable conclusions are where they assume that the traumatic treatment is the actual cause of difference, rather than malnutrition, poor education, heritable differences and other factors that shape brains.

BPD is now being considered to be a neurodevelopmental disorder, much like Autism and ADHD. “Although borderline personality disorder is classified as a personality disorder, many studies have developed arguments in favor of a neurodevelopmental origin” [“Borderline personality: revisiting its classification as a neurodevelopmental disorder”, 2025]. If this is correct, then the argument can be made that BPD is a neurotype much like Autism and ADHD appear to be. This is still a new way of thinking, so watch this space. I argue later that all of the differences that we find in BPD are better explained by other conditions.

Environmental Conditions

“Environmental Conditions” sounds like an authoritative cause for BPD, until you start to try to work out what that actually means. We know that background pollution is not a factor for this condition, poverty is correlated but not causative, and poor role models are also correlated although not strongly causative. After this, what do they mean by “environmental conditions”?

Poverty is correlated in that many people who are diagnosed with BPD. Initially this looks good – however, there are two factors interferring with this.

1. Does poverty cause BPD, or does BPD cause poverty? More often than not, BPD causes poverty.
2. People who are born into poverty often have parents struggling with their own difficulties, where their struggles caused poverty.

The second factor in poverty above is pretty much the best explanation for poor role models – heritable poor mental health often makes it challenging for your parents, who passed on their struggles to you. More often than not, this is a neurotype more than poor education, although poor education can be a factor in this too, but that poor education is compounded by poverty.

Aetiology Summary

Assuming that BPD is a real unique diagnosis, the explanations for cause are very poor.

Treatment

The Medical Model treatment for BPD is not good. Generally medications that either don’t work or work very poorly are prescribed, and sometimes people try various talking therapies which are ill fitting.

Medication

The most common three categories of medications that are prescribed for BPD are:

• SSRI to try to manage mood
• Antipsychotics to manage impulsiveness and rage
• Antiepileptics to slow the person down

Most of the medications in these categories frequently make no noticeable difference to the person’s symptoms or discomfort, and when they do, they are mild at best. These medications do make it easier for you to be managed by others. The side effects are mostly mild but can be fairly awful.

Within these categories, and a few others, are medications that I have found work fairly well for people diagnosed with BPD.

Talking Therapies

Talking Therapies is what psychologists, counsellors etc do.

Talking Therapies that do not work well is textbook CBT (self help by the book rather than a master), Trauma Therapy (most of the time) or pseudoscience like EMDR, art therapy or schema.

The best talking therapy for BPD is a form of CBT (Cognitive Behaviour Therapy) specifically tailored to BPD called DBT (Dialectical Behaviour Therapy), created by Marsha Linehan.

Stigma

BPD is considered very hard to treat and manage. We cover elsewhere why BPD is probably the wrong diagnosis. If you are treating the wrong condition, your treatments likely won’t work.

Victim Blaming

This has led to professionals in the health industry holding a strong Stigma against BPD rather than, in my opinion, recognising their own failings as a therapist or the failings in the diagnosis.

• Part of this is what I cover in this article about BPD not being an accurate diagnosis, leading to poor treatment plans
• Part of this is to do with most therapists didn’t get taught how to heal
• Part of this is that therapists ignore the biological side of people’s conditions; thinking that will power and motivation are enough to overcome biologically driven symptoms

Rebranding

In an effort to change the stigma, BPD has been rebranded a few times. We professionals know this, so it doesn’t at all work. We read

• BPD – Borderline Personality Disorder
• EUPD – Emotionally Unstable Personality Disorder
• cPTSD – complex Post Traumatic Stress Disorder

as the same condition.

Changing the brand name doesn’t change the problem, it just confuses people who are diagnosed with any of these 3 conditions.

Systemic Failures

A common experience that you may have if you are diagnosed with BPD is decompensation (worsening mental health with likely behavioural issues) when systems are not following the rules.

For example, hospitals have a strong set of rules that most professionals don’t actually follow. Each professional (nurse, doctor, orderly etc) kind of follows the rules in their own way. A person diagnosed with BPD, and many Autistic people, struggle with those inconsistencies. Surely the rules exist for a reason? Surely this is people’s lives we are talking about? And yet, the next professional won’t do things the same way as the prior professional, because their interpretation of the rules is different. The rules are more kind of guidelines than rules per se – except each professional will agree that these are actual rules and they are very important. This often provokes a strong emotional and behavioural response. Hospitals know that people with BPD don’t respond well in their environment, so generally use the unwritten policy of “patch them up and kick them out” to protect both the diagnosed person and the hospital.

While challenging to understand, this really is for your good – the longer you stay in hospital, the more likely you are to decompensate, so the faster they can get you out, the safer it is for you. They balance this safer for you against the risk of early release for most other people, and the risk is higher keeping you in hospital. Most hospitals just are not rigid enough in rules adherence to manage you well, and the decision makers know it – although the staff are likely to actually blame you for it, instead of accepting responsibility for the failure on themselves.

Most therapists don’t like BPD either. They try to do all of the usual trauma based therapies, but they really don’t work very well, because BPD isn’t generally caused by trauma, despite the common aetiology theories. While BPD does respond well to medication, it has to be the right medication, and the default BPD treatment plan still prioritises medications that don’t work very well. As noted in Medication Treatment, poor medication means poor cognition and emotional regulation, which makes it hard for any good talking therapy to actually work. This means that talking therapy has a poor response. Much like the hospitals, most therapists blame you and your BPD diagnosis on the poor result rather than acknowledged that what they are doing is not working and perhaps they should make some changes.

The stigma is very strong for BPD, which then heightens Rejection Sensitivity, which feeds back to increasing the BPD acting out behaviours and internal dysregulation.

BPD vs Autism and ADHD

My Anecdote of Doubt

While the plural of anecdote is not data, it is a good starting point for looking at truth. With that in mind, here is my anecdote.

When I went into private practice, leaving a team of 10-15 specialist therapists in both general complex therapy and suicide intervention, a number of clients followed me. Of those clients, around 30 were diagnosed with BPD. At the time, I had concerns that BPD was not the proper diagnosis for any of them. I was not well versed in Autism or ADHD at the time, but I had met a few openly Autistic and ADHD people who were fairly unmasked (not hiding their traits). I began to dig in to Autism and ADHD to understand better what they were really about.

As part of my rabbit hole, I created a grid of symptoms that my clients had – for BPD, Autism and ADHD. I then noticed that quite a few of the symptoms effectively the same. For the other symptoms, I noticed that while the description for some things were different, the fundamental concept and feel beneath many were the same. I switched from looking for similarities to looking for differences, and I really didn’t find any.

* This is good scientific practice. Notice a pattern; form a hypothesis to explain why; use the hypothesis to create a prediction if it is true and a prediction for if it is false; test to see what happens and compare to the true / false predictions.

I encouraged my roughly 30 clients to go and see an ADHD Psychiatrist (mostly different psychiatrists for each client) for assessment. All bar 2 did go to see ADHD Psychiatrists and were re-diagnosed with ADHD. All bar 2 of those re-diagnosed clients benefitted from medication – 26/30. Many years later, 1 of those is now benefiting from ADHD medications because we addressed their oestradiol deficiency (oestradiol is key in making Dopamine, Dopamine improvement is the key for treating ADHD) – 27 / 30. One of the client’s that didn’t see an ADHD Psychiatrist is due to not being able to find one who will accept their complex case, but none the less we work on the assumption of ADHD and they have done better because of it – 28 / 30, one that didn’t go to see an ADHD psychiatrist.

These were not cherry picked clients, however there may be a self selection bias in that these were people who found my brand of therapy worked well for them such that they followed me when I moved practice. My bounce rate is very low (bounce means meet me once and don’t come back), and the people who came to see me were given were generally because I was available at the time (fairly random) – only a few got moved to see me because their existing therapist was struggling.

For every new client I have come to see me who has a diagnosis of BPD, we reassess to see if ADHD is more accurate, refer for ADHD diagnosis and treatment, and so far no one has not benefited from it.

From my professional experience, for around a decade

• I have found that BPD is not a good diagnosis for anyone I have worked with
• Mostly Autism and ADHD has better described the majority of symptoms of concern
• ADHD medication has worked better for the client
• Combined ADHD Therapy, Autism Therapy, DBT and sometimes Trauma Therapy has worked the best for good outcomes

But – this is just one professional’s anecdote.

When a client is referred to me with a diagnosis of BPD, considering my doubts about the diagnosis, what benefit do the 3 variant representations of BPD give me as a therapist?

Mood

At the least, this tells me that my new client is considered to have significant problems regulating their mood. That leads to:

• Strong chance of thoughts of self harm and suicidal ideation, with some risk of acting on those
• Risk of aggression
• Black and White thinking when distressed

Cognition

This also informs me that there are likely frequent times when cognition (thinking and solving) is compromised, often co-occurring with mood dysregulation as above, but also sometimes without it. This adds times of :

• Impulse control problems
• False conclusions
• Bad logic decisions
• Poor memory
• Time blindness

Social

Other traits to expect to see:

• Rejection sensitivity on a background of social anxiety
• Poor boundaries
• Chaotic friendships
• Probable social abuse

As a background, I expect my new client will likely have troublesome parents and or an intimate relationship (now or ex) that was abusive.

Management

While these are going to be some strong expectations upon going in, I try to be cognisant to the fact that people are variable and so any one or more of these may not be accurate – so assess first.

To address these, if present, we work on:

• Appropriate Medication and Accurate Diagnosis
• Interoception and mood management
• Crisis Management and Safety Plans
• Conflict and Abuse Management, Domestic Violence, and the Traffic Light System
• Where needed, Trauma Therapy

Conclusion

BPD is often a dead end diagnosis that leads to poor results, primarily in my opinion, due to it being inaccurate and trumped by Autism and ADHD diagnosis. There is value in recognising that BPD is a description of difficulties associated with mood and cognitive dysfunction with a high likelihood of harmful behaviours and social conflict more than it is a thing in and of itself with a proper aetiology, unique symptoms, pathology and treatment plan. Instead it helps inform the therapist of specific likely issues to ensure are management on the way to a proper diagnosis and complete treatment.

The BPD community has created a number of terms to describe their experience that is quite powerful and some management methods that are very useful. Good therapists should keep up with these and bring them into their practice.