FAQ: Is a personality disorder a mental illness or a character flaw?

[BPDFamily.com]

My question is:

Is this behaviour really a Mental Illness or just character flaws, or lack of good parenting of values, or anger management issues, petty or superficial or wrong thinking, or deficiency in cognition ... .are some of us (on some lists) too quick to label normal ups/downs, disagreements, or even some upsets or conflicts in a marr/rel as BPD? [small (non-physical) fights & arguments are normal, o/w it is not a normal rel]!

Mental Illness implies somewhat psychotic or non reality or simply paranoia type of mindset... .too harsh a term?

... .whereas - what we see in BPD is more about extreme sensitivity about rejection (aren't we all, non-BP's also, a little afraid of being rejected?) OR ... .Anger Management (A/M) issues, OR few character flaws to "lie" or misrepresent, ... .and we all ( non-BP's and/or "normal" perceive things differently  (basic Pysch 101 course tells us that),... .so are we too eager s/t on some posts to label such thinking or behaviour as MI?

[KindSoul-AA99]

My question is:

Is this behaviour really a Mental Illness or just character flaws, or lack of good parenting of values, or anger management issues, petty or superficial or wrong thinking, or deficiency in cognition ... .are some of us (on some lists) too quick to label normal ups/downs, disagreements, or even some upsets or conflicts in a marr/rel as BPD? [small (non-physical) fights & arguments are normal, o/w it is not a normal rel]!

Mental Illness implies somewhat psychotic or non reality or simply paranoia type of mindset... .too harsh a term?

... .whereas - what we see in BPD is more about extreme sensitivity about rejection (aren't we all, non-BP's also, a little afraid of being rejected?) OR ... .Anger Management (A/M) issues, OR few character flaws to "lie" or misrepresent, ... .and we all ( non-BP's and/or "normal" perceive things differently  (basic Pysch 101 course tells us that),... .so are we too eager s/t on some posts to label such thinking or behaviour as MI?

[GENERAL ANNOUNCEMENT]

GENERAL ANNOUNCEMENT This board is intended for general questions about BPD and other personality disorders, trait definitions, and related therapies and diagnostics. Topics should be formatted as a question. Please do not host topics related to the specific pwBPD in your life - those discussions should be hosted on an appropraite [L1] - [L4] board. You will find indepth information provided by our senior members in our workshop board discussions (click here).

[Isitme]

You raise some interesting questions.  The nature vs. nurture debate is as old as time.

In the midst of your ponderings, don't forget that parents are not the only influence in a child's life.  We have many sincere and good people represented on the "Raising a child with BPD" board who are bewildered as to how this happened to their family.  There's no doubt that research shows that abuse correlates with BPD.  But that can come from many directions, not just FOO.

I can relate though.  With my uBPD SIL, an unrelated adult, it's easy to think, she's not sick, she's just a selfish jerk.  It's certainly a complicated disorder.

[Skip]

I believe behavioral scientists made some headway toward an answer to this question in 2008.

People with borderline personality disorder suffer from an inability to understand the actions of others. They frequently have unstable relationships, fly into rages inappropriately, or become depressed and cannot trust the actions and motives of other people.

"This may be the first time a physical signature for a personality disorder has been identified," said Dr. P. Read Montague, professor of neuroscience at Baylor College of Medicine and director of the BCM Brown Foundation Human Neuroimaging Laboratory.

"For the first time, to my knowledge, we have a specific brain association for people with a personality disorder," said Dr. Stuart Yudofsky, chair of the Menninger Department of Psychiatry and Behavioral Sciences at BCM. "It's new and different because it's not a lesion (or injury to the brain) but it is a difference in perceiving information that comes from an interaction." That is the area where people with borderline personality disorder have the most problem.

"It's important that this biological signature has been identified," said King-Casas. "It's not just a matter of bad attitudes or a lack of will."

www.bcm.edu/news/packages/trust.cfm

[athena444]

I don't want to make anyone upset or angry but it seems to me a lot of the behaviors of the BP's are choices.  Could a person to some extent just decide not to act that way?

[peacebaby]

I don't think any of BPD is a choice. No one would choose to be that kind of crazy.

But I believe that there *are* choices they can make that can lead away from BPD. They can choose to admit to themselves that they have a serious problem--they know it, but it can be hard for them to admit because it's so scary. Then they can make the choice that they don't want to live this way anymore, they want to try to feel better. Which is also terrifying--they are used to being as they are, they don't know another way and fear they *can't* be happy, so why bother? Then they have to move past this and choose to seek help, again terrifying because it means they have to deal with all their issues. And then they have to choose to take the help that they have sought--really work their DBT program, and that's *hard*. For all of these things they have to get past really strong defenses and tricks they play on themselves--they have to choose to be really brave and motivated and hopeful and open and introspective.

So, I don't think their behavior is a choice, nor are their feelings. But to stay there, to not seek help, that is a choice.

Peacebaby

 

[Phoenix10]

The therapist I am currently seeing, who has a great deal of experience with BPD and other PD's, has often said, "They do have a choice in how they behave"

Possibly what they may lack is the skills to behave in a more positive way. And that is where therapy comes in. My understanding of BPD is that their whole thinking/feeling/emotional processess are skewed, usually as a result of abuse in childhood. The styles of therapy that are known to be very beneficial to BPD sufferers such as CBT and DBT, aims to identify the skewed thoughts etc, and to try and change them to more positive and realistic ones ( this is a very simplistic explanation)

I suppose at the root of BPD is fear, and fear is an incredibly powerful thing. The choice I suppose, for any of us, is to  CHOOSE to confront and overcome our fears, whether we have BPD or not.

The BPD I had in my life, WAS very aware of her past behaviours with relationships, but CHOSE to do very little about it. She just carried on repeating the same old destructive patterns of behaviour, as in her mind, that was easier than confronting her fears and seeking long term therapy. And that was her CHOICE

[lostinspace2]

Does anyone know if the genetic predisposition for BPD has ever been specificially identified in those who do not go on to develop the disorder? Surely a genetic predisposition to hypersensitivity means that you will  develop the disorder regardless of a good home environment. I'm thinking here of outside factors such as a competitive/bullying, invalidating school environment (from age 4 in my part of the world). Then again does psychological theory not cite that personality disorder is irreversibly developed in infancy, by age 2 I believe. ?

[Bitzee]

I don't think the genetic predisposition has been specifically identified in anyone.  I believe it's only a theory... .not a biologically proven fact.

Thy say the predisposition to sensitivity need not develop into BPD if the child is properly validated... .they will then be able to learn to regulate their emotions.  There is much speculation that BPD results from an inborn sensitive nature in combination with a lack of certain early developmental needs being met.  If this is the case, then outside factors, such as school, would come after the fact.

[Nomoreblues]

In a previous study, Trull and research colleagues examined data from 5,496 twins in the Netherlands, Belgium and Australia to assess the extent of genetic influence on the manifestation of BPD features. The research team found that 42 percent of variation in BPD features was attributable to genetic influences and 58 percent was attributable to environmental influences, and this was consistent across the three countries. In addition, Trull and colleagues found that there was no significant difference in heritability rates between men and women, and that young adults displayed more BPD features then older adults.

As far as I know, genetic predisposition causes a bigger probability of BPD developing. Some pro's say that someone with the disposition doesn't necessarily have to become BP but bad circumstances (emotional or physical abuse) are a guarantee if the genetic stuff is there. And because it's there parent's or one of thme are likely to show BP or inadequate behavior of some sorts themselves, the problem is passed on. I also think that BP can develop without genetic disposition, I think as a result of severe abuse.

I tend to look at it as a mental illness but also as a way of being: they grow up in that world are or become that way and live that way, it's their universe and reality. No wonder it is so difficult for them to get out... .Image you are always taught that the sky is green, are raised by people who think the sky is green and manage to always find poeple around you who will tell you and affrim you that it is so (mainly because they are not interested in you as most people aren't really inetersted in most other people and so they say "sure it's green" to get rid of the discussion" and I would tell you that it is blue, what would you do? Believe me? Critize your own world when you don't need to? and if you would then what, recreate an entire new world? So we love them. promise them to take them seriously and tell them what they can't handle: you are strange, act normal please... .

I think it's blue... .;-)

NMB.

[Bitzee]

I'd think frequent hospitalizations with invasive procedures at a very early age when one is pre-verbal and incapable of forming conscious memories of the events could have quite an impact on an individual.  For instance, how does a parent validate the feelings of a child who is not yet capable of reasoning?  And how does a child incapable of conscious memory or verbal expression ever process these events?  This must also be an upsetting and highly stressful experience for the parents, as well.  For a child with the predisposition, I'd think a history of early hospitalizations and surgeries could definitely be a significant environmental trigger. 

Early separation from the caregivers is also cited frequently in the histories of those who develop BPD. 

I think some children and the situations that arise are very difficult to validate... .very difficult for ANYONE to validate.  There is definitely not always abuse, or intentional neglect or invalidation.  There can be very disruptive circumstances and if the child is predisposed to the Borderline type temperament/nature,  they will develop the disorder.  Whereas, a child of a different nature would not develop the disorder.

[MomToOne]

We adopted our d when she was a year old. She is 17 now, and began exhibiting symptoms at the onset of puberty. A couple of years ago she found her birthparents on MySpace. After talking to them, we found out d's behavior and diagnoses matched the birthmother's almost identically and at the same ages, too. Birthmother's mom and grandmother also had BPD, substance abuse issues, etc. It must be genetic in this case.

[GENERAL ANNOUNCEMENT]

GENERAL ANNOUNCEMENT This board is intended for general questions about BPD and other personality disorders, trait definitions, and related therapies and diagnostics. Topics should be formatted as a question. Please do not host topics related to the specific pwBPD in your life - those discussions should be hosted on an appropraite [L1] - [L4] board. You will find indepth information provided by our senior members in our workshop board discussions (click here).

[Lil_Arch]

Peacebaby:

My Husband Choose therapy he wants to get better... Full time therapy that is 15 weeks long. He had made an attempt once befor but because of his work and our money was tight he couldn't finish it. He is going back next semester for it. And Hopefully by then he will be on Short term Disibility so he can do this its basically a full time job... 15 weeks long 8 hours a day... Its INTENSE... I hope he gets disibility so he can FINALLY get better

[peacebaby]

Li'l Arch--That's so cool for you both! My SO went through the same thing--got accepted at this DBT program 5 years ago but couldn't get the dissability or insurance and had to work. But last year she finally got everything she needed. Her course is 3 hours a day, 5 days a week for 6 months or longer. I think these intense courses really work well for someone who's into learning and changing, but it could be stressful due to how intense it is. My SO is hanging in very well. Thanks for sharing that! So my SO is not the only BPD around here making a healthy choice all on their own for their happiness!

Peacebaby

[Skip]

I think of it like a food addiction... .they may know better... .they may want to stop... .but they are fighting natural instincts (esp during stress)... .and there are the times a person can't stop... .and there are ties when they simply indulge... .

I think, in some cases, people suffering with BPD feel "out of control", and they bully to get "control" or "worth".

This is why structure works - they are very here and now - like making good meals and keeping junk food out of the house.  Food bingers can keep it together in public, too.

[C12P21]

I think BPD is like other diagnosis-people have variations across the spectrum of their behavior. I suspect their emotions are crippling, and like a drowning person they will grab whatever it takes to save themselves from drowning in their fears. However, if their behavior is not a choice, why are some successful in their work? And why do they not abuse their co-workers. My lay opinion is this, BPD will abuse those whom they realize they can manipulate and control. The best protection I have found is to have clear boundaries, and no contact.

[Auspicious]

I think of it like a food addiction... .they may know better... .they may want to stop... .but they are fighting natural instincts (esp during stress)... .and there are the times a person can't stop... .and there are ties when they simply indulge... .

I think, in some cases, people suffering with BPD feel "out of control", and they bully to get "control" or "worth".

This is why structure works - they are very here and now - like making good meals and keeping junk food out of the house.  Food bingers can keep it together in public, too.

It's the best analogy I've heard.

"But she never binges on broccoli ... .doesn't that prove she could simply choose not to binge on donuts?"

[gertrude]

I have heard said that the person in the relationship who cares the least has the most power.  That is the truth.  Yes, there is certainly co dependency in our relationships.  And I think that they have an intuitive way of knowing who will be soft and pliable and that is who they go after.  Well, I am soft and pliable and fairly easy going.  I don't want to have to change that - I would rather be with someone who will not take advantage of it.  But I'm fairly certain after the agony of my BPD relationship, I will not give someone a second opportunity to be abusive to me.  I'm pretty sure I'm done with that.

I believe BPD is not a choice.  The prevailing thinking is that there is a sociobiological causation - some genetic inclination combined with a tough environmental background.  I read studies that said that the amagdyla (did I spell that right?) of the brain, the portion of the brain that controls emotions, is shaped differently, or smaller in someone with BPD.  Perhaps their brain develops in conjunction with their thought patterns and not the other way around.

I cannot believe that my ex wanted our relationship to end - I know he didn't.  I don't think he wanted his previous relationships to end either.  I just do not think he can control his behavior.  I have chosen to give him a pass and just get away.  That was the best way I could handle it.  Carol

[waybird]

I have heard said that the person in the relationship who cares the least has the most power.  That is the truth.  Yes, there is certainly co dependency in our relationships.  And I think that they have an intuitive way of knowing who will be soft and pliable and that is who they go after.  Well, I am soft and pliable and fairly easy going.  I don't want to have to change that - I would rather be with someone who will not take advantage of it.  But I'm fairly certain after the agony of my BPD relationship, I will not give someone a second opportunity to be abusive to me.  I'm pretty sure I'm done with that.

Thanks to you Gertrude, and to BugsBunny, for responding to my question about caring.  I am so stuck with this because I feel as if I hardened up - become not so "soft and pliable," then I will be no better than the BPD in my life.  My uBPDmom is the epitome what is considered callous and mean, yet it is the very thing she accuses me of being.  So, if I harden - or "grow a thicker skin" as my hubby says, I fear I will morph into some sort of BPD concoction like her.  I don't know how to resolve this.

Gertrude... .I have also heard that the person in the relationship who cares the least has the most power.  But, what if you aren't after power, but authentic relationships with people?  Maybe there is no such thing with a BPD. 

Bugs... .I like your theory on self-preservation.  That makes sense to me.  I just feel like I have been almost brainwashed to care so that my momster would have her needs met.  To not care means bad things will happen and I will be a bad person - like her.  Hence, I continually get sacrificed and hurt because of it.  Is this codependency?  Or am I just afraid to stand up for myself, create my own space and say no?  How can a person choose to care in the right ways?

Ugh.   

[Auspicious]

I have also heard that the person in the relationship who cares the least has the most power.  But, what if you aren't after power, but authentic relationships with people?  Maybe there is no such thing with a BPD.  

That's why on the Staying board we talk about various tools to stay, such as emotional validation and boundaries.

You develop a kind of jujutsu ... .when the BPD makes the mistake of trying to make it be about power, you choose not to play. You aren't there when their blows land.

You protect yourself with boundaries, and you connect with emotional validation.

[survivorof2]

Great question!

I like what one person said: Having it is no choice, but dealing with it is a choice... .or something like that.

My feeling is as long as they have someone enmeshed with them, "validating" them, or a victim to torment, no they see no reason to deal with it.

[Auspicious]

My feeling is as long as they have someone enmeshed with them, "validating" them, or a victim to torment, no they see no reason to deal with it.

I agree that having an enabler makes it less likely that they will seek help.

However, I need to point out that the validation that we talk about on this site is the opposite of enmeshment and being a victim.

[mindatrisk]

I thought that a mental illness was to do with problems with the brain like a chemical imbalance whereas a personality disorder has nothing to do with any problems with the brain, it is just how their personality has formed due to whatever reasons. 

[thisblonde]

Lots of things fall under the Mental Disorder group, such as BPD and even eating disorders.  A personality disorder is just one of many mental illnesses.  Mental illness is just a broad term and category.   Whether a person is "mentally incompetent" is a completely different issue.    Majority of people with mental disorders know the difference between right and wrong and could never pass the mental incompetency test required to absolve one from the consequences of their bad behavior/poor choices, etc. and be considered "mentally incompetent".  

I haven't heard of a BPD being considered mentally incompetent.  The few cases I'm familiar with involve severe Schizos.   Hope this helps... .

 

 

[OutofOz]

Maybe some of the confusion comes from the term "mental illness".  I don't think most mental health professionals would use that term over "psychological condition".  The DSM IV is a manual of psychological conditions.  And a personality disorder is a psychological condition inasmuch as it's a cluster of psychological traits, but is controversial as a "mental illness" because THAT'S THEIR PERSONALITY.  If it doesn't affect their lives negatively to them, there's nothing saying that it's illness to have that personality.  You COULD look at it as just a personality type.

Borderline is a little controversial too, because the brain function studies have found where there are parts of the brain smaller or not functioning as actively as in normal brains.  I don't think anyone has processed exactly how to work with this--it's NOT just a set of thoughts going through a normal-looking brain.  Another thing that makes mental health professionals have to sit up and take more notice is the suicide rate.  It's harder to argue that you can leave someone to just have their personality like it is when 10% of those people are going to kill themselves.  Narcissistic personality disorder on the other hand--also very annoying to others.  But they're not likely to commit suicide or physically harm others.  So psychologists help them if they ask for it, and basically leave them alone if they don't. 

I'm sure there is work being done in this area.  ADHD patients also have areas of their brain that are often smaller or less functional, and drugs have been developed to help them.  BPD is just a harder nut to crack with pharmacology--gotta find the right drug AND get it to work in the right part of the brain.  Harder than you'd think.

Anyway, my $.02.  Pschologists and psychiatrists and the DSM IV are just holding on and classifying things as best they can in a messy situation. 

OO

[Hannahbanana]

I thought that a mental illness was to do with problems with the brain like a chemical imbalance whereas a personality disorder has nothing to do with any problems with the brain, it is just how their personality has formed due to whatever reasons. 

When a child is traumatised growing up (which the majority of BPD individuals have been) the brain can form differently than someone who is not traumatised, leading to an imablance of certain chemicals.  Plus, there is no absolute evidence that borderline is not controlled by chemical imbalance in the brain.  When someone feels angry, overly sad or upset, it's the chemicals in the brain that more or less rule the roost with your ability to stay calm and your inability... .it's also a case of learning to ignore what your body is telling you and remaining calm or calming down quicker, for someone with BPD, this must be tremendously difficult to do.

www.psychcentral.com/news/2009/09/04/brain-scans-clarify-borderline-personality-disorder/8184.html

[Hannahbanana]

Have there been any studies that confirm the trauma as a child that many BP's claim? Could the claims of childhood trauma be just as much a fabrication as the claims of abuse they claim against us as adults? The only reason i ask this is because my stbx claimed to not really have any memories of her childhood and could not really point to a specific trauma or event. I know blocked memories are also not unusual in chidhood trauma cases,but considering the BPD grasp of truth and reality I think in depth studies of BP's childhoods need to be done to verify if the trauma and abuse actually occurred.

During my university years, i came across numerous studies of childhood abuse victims and it may surprise you to know that many, many many victims of childhood abuse, do not say they were abused.  A lot of people who were abused: borderline, co-dependant nons, schizophrenic, bipolar, depressed, seemingly societally normal and so on... .deny they were abused or keep quiet about being abused and it is mainly their everyday interaction with people, their reactions to situations, stressful or otherwise, coping mechanisms to life, that give the game away.  I think you will find that it is extremely rare that someone claims they were abused when they were not, yes people do it, but bear in mind that what may not be abuse to you, may be abuse to the next man.  Victims of childhood abuse can also have selective memory and become so good at locking away painful memories during their childhood, that they do it unwittingly throughout their lives... .this is very common.  So, the fact that your ex cannot point to a specific fact, does not mean the claim that he/she was abused, is a lie.

The claims they make against us as adults may not be a fabrication or lie to them, they may truly believe they are being abused by us.  I did not abuse my ex in any way, but i have to accept that his mind does not work in the same way mine does and if he thinks i was abusive because of my tone, my facial expression, me ignoring his calls etc, then in his mind, somewhere, this is probably abuse to him.  He just does not have the mental capacity to realise that it was all reactive to what i was experiencing from him/  I think someone with BPD feels abused by us because, as has been written, they have the emotional capacity analogous of a 3rd degree burns victim... .not because they are telling lies deliberately.  My ex used to say to my face that i was abusing him, even though i had just encountered hours of it from him and simply reacted by arguing back with him once in a blue moon, i could see by his reaction that he truly felt attacked.

[Auspicious]

Thoughts and feelings are embodied in the brain's electro-chemistry. Chemicals can affect thoughts. Thoughts can affect chemicals.

Brain scans look different after traumatic experiences, and they also look different after months of therapy.

The current consensus appears to be that you can't treat bipolar with just therapy; you need meds. And you can't treat BPD with just meds; you need therapy.

But both are mental illnesses.

[DaraChaos]

BPD is very much recognized as a legitimate mental illness. The DSM classifies mental illnesses according to an Axis system.  For example, mood disorders such as Major Depression, Bipolar Disorder, Dysthymic Disorder, etc. are Axis I illnesses.  Basically, these disorders can be treated with medication, preferably along with psychotherapy.  Personality disorders, however, are classified as Axis II, and can further be broken down according to "cluster", such as Axis II, Cluster A,B, or C.  Examples of Axis II, Cluster B would be BPD, NPD, Hystrionic PD, and Anti-Social PD.  These disorders do not really respond to medication, as they are "hard-wired" into the individual's brain.  Nearly everything I've read and heard does suggest that most BPDs did have something traumatic happen to them in early childhood, to varying degrees.  Anyway, personality disorders are not easily fixed, and it seems that they can be improved, somewhat, ONLY if the person with a PD accepts that they have a problem and wants to try to fix it.  This is what makes it so difficult for the PD's family and friends!

[MaybeSo]

Marsha Linahan, the founder of DBT, has worked for over 30 years with this population.  She purports a genetic predisposistion that is turned on or exacerbated by either classic trauma eg., physical or sexual abuse, or a more subtle form of trauma that occurs over a long period time that is often described as an ongoing perceived invalidating environment... .meaning years of a child saying for example... .'I feel hungry' and those who care for him saying 'no you're not'... .or 'you shouldn't feel that way'... .and it's this combination, a genetic sensitivity or predisposition combined with what is perceived as an invalidating/traumatizing environment, that leads to BPD.

The only reason i ask this is because my stbx claimed to not really have any memories of her childhood and could not really point to a specific trauma or event.

Not really having any memories of childhood is odd in an off itself, as a therapist, I would immediately be thinking... .trauma, either emotional or physical.  My BPDbf never could really conjur up much memory of childhood either... .that is slowly changing with therapy.  His mother would hit him with a belt... .but nothing that would probably qualify for a CPS report.  'You shouldn't feel that way' was like a mantra in his home. His mother is most likely NPD... .she is completely self absorbed and self directed.  She is looking for mirroring constantly... .she does not have the capacity to mirror or lend her ego strength to a child.  Children need this to develop normally in an emotional way... .I cannot even imagine what it was like for him as a child to be seeking connection with this woman.  He was fed, and schooled, he's smart... .but not about what goes on between two people in an emotional way or his own emotions.  He craves love and affection and before DBT, would try to illicit love and affection in some very self sabatoging ways... .big surprise.  When he feels abandonment or love/connection does not seem to be working out... .he panics, and again,  he cannot use the smart part of his brain that was schooled in math and science to handle the panic, he has to use the part that regulates emotion, and that was never tought in his home, indeed, in his home, what was modeled was either no emotion at all, out of control emotion, or manipulative mind games.  Even if he were never hit... .that is not an optimal environment for a child to develop any form of emotinal intelligence, and he is no doubt senstive and predisposed as I see that this appears to run in the family. 

Another kid in the same family, might not exhibit BPD... .maybe they did not carry the same genetic predisposition, maybe they had a few more social or environmental factors that made them more resilient such they could ignore or shake off or better cope with an invalidating environment.  We are all endlessly unique.     

It is rare to see BPD without it co-occuring with other Axis I disorders like depression and anxiety... .many do respond well to drugs because of this and some drugs are even helpful with the imlpulsive component, so while no drug cures BPD... .it is not accurate to say drugs can't help... .because for many they help tremendously.  For some, without drugs... .it would be difficult to sit and gain anything from therapy.

And yes, the environment, stress, what is going on around you... .can have an impact on your brain function and over time can acutally change the structure and the complex exchange of chemicals that inform our emotions and consequent behavior.

There is talk of moving BPD from Axis II to Axis I because there is empirically beneficial treatments now.  There has been talk for a while of renaming it Emotional Dysregulation Disorder becasue it is a more apt description and it's a step away from the years of negative stigma before it was better understood.  In one of the last lectures I attended this year, there was apparently talk of the possibility of viewing BPD as a sub type of bi polar disorder.  Well see what happens.   

[Auspicious]

I believe I read that the name comes from the idea that in the old Freudian system, they were thought to be on the "borderline" between "neurosis" and "psychosis".

If you tried to treat them as "merely" neurotic ... .well, no, they are more than that. But they aren't psychotically arguing with the sky or anything either ... .most of the time, anyway. So the thought was that they are on the "borderline" between the two, or frequently crossing back and forth.

Precisely why they are so confusing and hard to deal with for everyone around them, including treatment providers.