Borderline personality disorder in relationships: when the fear of abandonment runs everything

“I texted him at two. By half past he still hadn’t replied. I know he’s in a meeting, he told me this morning. And still, by four I had sent eleven messages. The first was ‘are you okay?’, the last was ‘never mind, just go, everyone leaves anyway’. When he rang I cried with relief and at the same time felt so ashamed I wanted to disappear.”

Anyone who does not know this from the inside sees drama, exaggeration or manipulation. Anyone who does know it understands that there was no choice in those two hours, only a wave that rose faster than it could be stopped. And a third person, the one in the meeting, stares at his phone and cannot understand how a late reply turned into the end of the world.

This post is about borderline personality disorder and what it does to relationships, above all the fear of abandonment at its core. I am writing it for two kinds of reader: for you, if you recognise yourself in the scene, and for you, if you live alongside someone like this. One thing I will not do: guess from a description who has the disorder. I cannot do that, and neither can you.

A name that sounds worse than it is

The name itself is unfortunate. “Borderline” is a leftover from an old idea that the condition sits on the border between neurosis and psychosis, and “personality disorder” sounds as if the person themselves were faulty. The ICD-10 classification used in Slovenia calls it emotionally unstable personality disorder, borderline type, which is at least a little more descriptive: at the forefront are emotions that rise fast, rise high and settle slowly.

The American manual DSM-5 describes the disorder with nine criteria, of which at least five must be present for a diagnosis: frantic efforts to avoid real or imagined abandonment, unstable and intense relationships, an unstable sense of self, risky impulsivity, self-harm or suicidal behaviour, marked mood reactivity, a chronic feeling of emptiness, intense anger that is hard to control, and transient paranoia or a sense of detachment from oneself under stress. Even from this you can see that two people with the same diagnosis may share only a single criterion.

The diagnosis is made by a psychiatrist or a clinical psychologist after a longer assessment, not by an online test and not by a partner after an argument. As a therapist in training in marriage and family therapy, I do not diagnose. I wrote about what a diagnosis does and does not tell you in A diagnosis is a map, not a name for you: what the ICD says and what it does not. With this diagnosis caution is especially called for, because the word, much like “narcissist”, is readily used as an insult for someone who is hard to be around. That habit is the subject of “Narcissist”: a word we reach for too quickly.

What the research says about the course

For a long time borderline personality disorder was considered lasting and almost untreatable. Long-term studies have overturned that picture. Mary Zanarini and colleagues followed 290 people who had been admitted to hospital with the disorder for ten years. In that time 93 per cent achieved a remission of symptoms lasting at least two years, meaning they no longer met the criteria for the diagnosis. About half also achieved recovery in the full sense of the word: remission plus good functioning at work and in relationships.

Taken together, those two figures tell an honest story. The stormiest symptoms settle in the great majority. What changes more slowly is the quieter part: the sense of emptiness, the loneliness, the difficulties at work and with closeness. So it matters whether a person gets help, and it matters what kind.

Why the fear of abandonment is so strong

The most influential explanation was offered by the American psychologist Marsha Linehan in her biosocial model, later extended by Sheila Crowell and colleagues. In this model two things meet. The first is an inborn emotional sensitivity: some people register emotion sooner and more strongly, and return to baseline more slowly. The second is an environment that does not validate those emotions. The child hears, again and again, that they are overreacting, that there is nothing to cry about, that they should pull themselves together. These may be openly violent or neglectful families, but they may also be perfectly ordinary ones that simply did not know how to be with a very sensitive child. Either way the child does not learn how an emotion is named and soothed, but does learn that others only hear them when they are very loud.

John Gunderson and Karlen Lyons-Ruth added an important emphasis: at the core of the disorder is interpersonal hypersensitivity. The nervous system is tuned to the smallest signs that the other person is moving away, a pause in the voice, a shorter message, a glance at the clock. This is close to what attachment theory describes as a disorganised pattern, in which closeness is at once the most wanted and the most dangerous thing. I wrote about it in Disorganised attachment: when the same person is both comfort and fear.

So the fear of abandonment is not the thought “he might leave me”. It is a bodily state in which the abandonment has already happened. And because it is unbearable, a person will do anything to make it stop.

What makes the loop cruel is that the very action meant to prevent abandonment brings it closest.

How it shows in a relationship

At the start everything is often very intense. The new person is “the only one who has ever understood me”. We call this stage idealisation: the other is all good, closeness is fast and complete. Since no human being can live up to that image, the first disappointment comes, and because disappointment is felt as betrayal, the image flips. The same person is suddenly cold, selfish, dangerous. This is not lying or calculation. In a state of alarm it is genuinely hard to hold in mind, at the same time, that someone loves you and that they have just hurt you.

From here come behaviours that those close by find hard to understand:

• Testing. “If you really love me, you’ll stay even when I push you away.” The pushing is a question, not an answer.
• “Go” and “don’t go” in the same minute. Both are sincere. The first is shame speaking, the second fear.
• Leaving first. Ending the relationship before the other can, because waiting is worse than losing.
• Emptiness when the other is absent. Not just missing them, but a feeling that without them you do not know who you are.
• Impulsive acts after an argument. Anything that quickly puts out an unbearable feeling.

These acts can include self-harm, which is common in this disorder and is most often not an attempt at blackmail but a way of surviving a feeling. I have given it a post of its own, Self-harm: what it really means and how to respond, so I will not summarise it here.

What the person on the other side goes through

Partners, parents and friends often describe a sense of walking on eggshells. They never know which sentence will set off the storm. They work hard to prove they will not leave, and the proof never holds beyond the next trigger. In time they begin to defend themselves, to explain, to correct the facts (“I told you I had a meeting”), and from the inside all of that sounds like one more piece of evidence that they do not understand.

In the tradition of dialectical behaviour therapy the central idea for this moment is validation. It does not mean you agree, and it does not mean you give in. It means you first recognise the emotion as understandable given how the other person experienced the situation, and only then give your side. A conversation like that might sound something like this (composed for illustration, not a real person):

“You said you’d be here at six. It’s seven. Obviously you don’t care.”
“I was late and I didn’t let you know. I can imagine that hour felt long.”
“It wasn’t long. It was awful. I thought you weren’t coming.”
“I believe you. I’d have a knot in my stomach too if I were waiting with no message. I do care, and I’m not going anywhere.”
“… Then why didn’t you text?”
“Because I forgot. That’s my mistake, not a sign that I don’t love you. Next time I’ll text before I leave the office.”

In this exchange he does not say her interpretation was right. He does not apologise for something he did not do, and he does not promise the impossible. He validates the feeling, owns his part and states a fact. It does not always work, but it works a good deal more often than a defence does.

DBT: an established treatment that I do not provide

In the late 1980s Marsha Linehan developed dialectical behaviour therapy (DBT) specifically for people who repeatedly harmed themselves and for whom standard treatments did not hold. In the first randomised trial, published in 1991, the women receiving DBT had, over one year, fewer episodes of self-harm, fewer days in hospital, and were less likely to drop out of treatment than those in treatment as usual. In 2011 Linehan said publicly that as a young woman she herself had spent a long time in hospital with similar difficulties. Her method carries that experience: it takes seriously how unbearable the feeling is, and at the same time asks for change.

The word “dialectical” means exactly that duality: I accept you as you are, and I expect you to learn to do things differently. The full programme generally comprises individual therapy, a skills training group, the option of brief telephone coaching in a crisis, and regular consultation among the therapists. The skills are divided into four modules.

DBT is not the only treatment with evidence behind it. A Cochrane review from 2020 finds that the most research has accumulated for DBT and for mentalisation-based therapy; others, such as schema therapy, have been studied too. The same review honestly adds that the effects are moderate and the certainty of the evidence is not high. Medication is not the main treatment for this disorder; a psychiatrist may prescribe it for accompanying difficulties, and that judgement is theirs.

Let me be clear about myself: I do not provide DBT. I am training in relational family therapy, which works with relationships and with what we bring into them from our family of origin. Anyone struggling with repeated self-harm, suicidal thoughts or very stormy crises needs specialised treatment first. Where it is available in Slovenia is best known to a psychiatrist or a clinical psychologist; the route to them generally runs through your GP.

An exercise: twenty minutes before you send

This exercise does not replace therapy. It rests, though, on a simple observation from the loop above: between alarm and action there is a short space, and practice can widen it. Use it when you feel the urge to send a message you already suspect you will regret.

1. Name the wave and rate it. Tell yourself: “This is the alarm.” Rate it from 0 to 10. Above seven is no place to decide about relationships.
2. Write the message, but not in the chat. Open your notes and write everything you want to say, uncensored. Then leave the phone in another room.
3. Give your body twenty minutes. Cold water on your face, a brisk walk round the block, or a few minutes of breathing with a longer out-breath. The aim is not for the feeling to vanish but for it to drop by two points.
4. Check the facts. On paper, make two columns: what I know for certain (“he hasn’t replied for two hours”) and what fear adds (“he doesn’t want me any more”). Add two other possible explanations.
5. Write one sentence that states the need. For example: “When there’s no reply for a long time, fear gets hold of me. Could you send me just a word when you have a moment?” Send that one. Save or delete what is in your notes.

The first few times it will probably not work, and that is not proof that you are hopeless. Emotion regulation is a skill most people learn in childhood, beside someone who soothed them. Those who did not have that chance learn it later, and with more repetitions.

If you are the one standing alongside

First: you are not their therapist and you cannot be their only source of safety. A relationship in which one person is forever proving that they will not leave exhausts both.

A few things do help, and they do not exclude one another. Validation, as in the dialogue above: the feeling first, then the facts. Predictability: if you say you will ring at eight, ring at eight. Small promises that hold are more calming than grand declarations. And boundaries, stated calmly and in advance: “When we’re shouting, I’ll go out for half an hour and then come back.” The second half of that sentence is the key. Leaving without announcing a return is, for someone with this fear, precisely the thing they dread. I described how to take such a break in Taking a break during an argument: how to step away without walking out.

A boundary is also this: you do not take over responsibility for their life. If they say they will do something to themselves if you leave, you neither ignore it nor try to rescue them alone: you call for help. That is not a betrayal. It tells them you are taking them seriously and that this is more than one person can carry.

When it is urgent

Suicidal thoughts and self-harm are more common in borderline personality disorder than in most other forms of mental distress and must always be taken seriously, even when they recur. If you are thinking of harming yourself, or you are worried about someone close, ring the mental health crisis line (Klic v duševni stiski) on 01 520 99 00 in Slovenia (every night from 7 pm to 7 am) or the Samarijan confidential helpline on 116 123 in Slovenia (24 hours a day, free of charge). Young people can ring the TOM helpline on 116 111 in Slovenia. In immediate danger call 112 in Slovenia. There is more on how to speak about these thoughts in When you think it would be better if you weren’t here: on suicidal thoughts.

Where this framework does not apply

A fear of abandonment does not in itself mean borderline personality disorder. A very similar alarm at a partner’s silence is familiar to many people whose difficulties are milder and narrower; I write about that in Anxious attachment: why a partner’s silence sets off the alarm. The after-effects of trauma, bipolar disorder or ADHD can produce a similar picture, and sometimes several things are present at once. Telling them apart is a professional’s job, not an article’s.

A second limit: sometimes the fear is not oversensitivity but accurate perception. If a partner really does disappear, lie, or threaten to leave in order to silence you, the problem is not in your nervous system. And if there is violence in the relationship, validation is not the answer. Nobody is obliged to meet blows, threats or control with understanding, whatever diagnosis the other person has. Where there is violence, the SOS helpline for women and children who are victims of violence is on 080 11 55 in Slovenia, and in an emergency the police are on 113 in Slovenia.

A third: a diagnosis is neither an excuse nor a verdict. The emotion is understandable, and the person is still responsible for the action. DBT teaches precisely those two things at once. And the stigma that clings to this diagnosis, among professionals too, does a great deal of harm: people hide it or avoid help, even though the research on its course shows that change is the rule rather than the exception.

Where do I come in? Not in treating the disorder. But therapy, in person in Ljubljana and also for English-speaking clients, can be a space for the relationship: for a couple in whom the loop from the first infographic has been turning for years, or for you, if you grew up beside someone with emotions this stormy and now carry that into your own relationships. When one of you has specialised treatment behind you or ahead of you, the two can complement each other.

What to remember

• At the core of borderline personality disorder is emotional and interpersonal hypersensitivity; the fear of abandonment is a bodily alarm, not calculation.
• The diagnosis is made by a psychiatrist or a clinical psychologist. Not by a partner, an online test or this post.
• The course is better than its reputation: in a ten-year study the great majority achieved a lasting remission of symptoms.
• DBT is an established treatment that teaches riding out the wave and choosing the action. I do not provide it; the route to it runs through a psychiatrist.
• Those close by help with validation, predictability and clear boundaries, not with rescuing. With suicidal thoughts, you call for help.