My sister has borderline personality disorder, and a decade after her diagnosis, I still struggle to

October 2024 · 16 minute read

Redeem now

Business Insider

My younger sister was diagnosed with borderline personality disorder (BPD) when she was 18 — and almost a decade later, I still don't know how to deal with it. 

Becky* is now 27, and lives on her own in an apartment a five-minute walk from where my mom and I live. 

At the moment, we rarely talk or text without the conversation ending in a furious argument where one of us blocks the other, but we weren't always like this.

In fact, we cherished each other when we were children, and during the majority of our teen years.

However, things have changed over time — and despite coming to understand more about her illness over the past nine years, my trust in her ran out of gas so long ago that any lingering fumes have almost completely evaporated. 

She's impulsive, a chronic liar, irrational, carries a deep self-hatred, and can't seem to form relationships with friends or partners that are stable and healthy. While I know much of this is because of her illness, it's made having a relationship with her next to impossible at times — though a part of me will always want to try.

We had an identical upbringing

Becky and I were born 23 months apart and have been brought up almost exactly the same.

We had near-idyllic and extremely privileged childhoods with a very devoted mom before our parents split when we were in our tweens, and battled it out with a messy divorce for most of our teen years. 

However, Becky had problems with behavior from very early on as a kid.

I can recall my mom taking her to child psychologists, behavioral specialists, tests for ADHD, craniosacral therapy (it was the 90s), and a dietitian who told her certain artificial additives and overly processed foods were making Becky hyper. Bye-bye, blue food colorants and fizzy drinks. 

Becky was finally diagnosed with BPD, the most commonly recognized personality disorder, around age 18, after years of difficulty trying to figure out as a family why she acted the way she did, and doing the best we could to pull her out of darkness she was unhappily flailing around in.

Brendan Kelly, Professor of Psychiatry at Trinity College Dublin, told Insider: "Very commonly, people say that a person has traits of borderline personality disorder, because there's a reluctance to make a diagnosis early on, partly because diagnosis does not automatically lead to a very clear treatment and treatment varies."

It's a tricky disorder to understand, even for professionals

BPD essentially boils down to the way an individual's brain reacts and perceives regular human emotions and relates to other people, according to the NHS.

Kelly said: "I think the key concept that they struggle with is the constancy, the consistency  — sticking with consistent treatment, consistent relationship, consistent job, and consistent position on anything.

"It's the difficulty living with the fact that life is rather dull and humdrum. Most days don't deliver conflict or excitement. I think that's something that is somehow intolerable, and leads to so much of this self-harming and self-destructive behaviour."

The disorder itself is quite a tricky mental health issue to understand. Not much is known about BPD, the identifying markers are hard to pick out as lots of people present with the characteristics some of the time, and professionals don't agree on all the information sufferers are given.

I don't think even my sister fully understands it, as she now assigns any and all bad behavior or erratic moods to her "BPD flaring up."

The NHS website characterizes BPD as:

As outlined in a previous Insider article, no one knows what causes BPD — there's no explanation for why it occurs in some but not others. A few mental health websites, such the charity Mind, suggest it could be partly down to genetics, and partly down to environmental factors, such as parental neglect or child abuse. 

I often wonder whether the trauma from warring parents could have exacerbated Becky's mental health struggles — I know I didn't make it out entirely unscathed, even with counseling.

Either way, all of us, Becky included, were relieved to finally have an explanation for her behavior when we got the offical news. As with any diagnosis, our next thought was — so how do we fix it?

Life threw Becky another curveball at age 22

To add fuel to an already complicated fire, Becky developed aggressive Hodgkin Lymphoma at age 22.

The kicker? When she got the news, she was holding onto a long-term job for the first time, while appearing like she wanted to get a grip on her mental health. 

Finding out she had cancer so young was a shock, and initially it was as if Becky's brain was given a jolt — her behavior noticeably improved for sustained periods of time. The sister I fiercely adore came back to me.

During the end of her first wave of chemotherapy, her body stopped responding, so the doctors changed tactics, but were pragmatic about her odds.

The second round of more intense chemo was the turning point where the BPD behaviors began to rear their ugly heads again.

However, this time arguing with her about her self-damaging actions came along with the guilt of shouting at a cancer patient. Having grown up with an acute concern for her welfare, it was an additional weight to carry.

One humdinger of a row was over her wanting to stay in a relationship with a cheating man who was allegedly going around telling people that having sex with Becky was like sleeping with a boy, because she had lost her hair from treatment.

Thankfully the tumors (and the guy) have now gone, and she's coming up to three years in remission. But, as her physical health has taken such a priority, her mental health — now with the added facet of cancer anxiety — has been pushed to one side regardless of mine and my mom's futile attempts to help.

My mom and I have tried it all when it comes to encouraging Becky to get help. EyeEm via Getty

"Some people say that borderline personality disorder is a condition where most of the distress is felt by other people rather than the person themselves," Kelly, who is also the author of '"Coping With Coronavirus: How To Stay Calm and Protect your Mental Health A Psychological Toolkit," explained. "So, the person themselves feels a great deal of distress, but a lot of the distress is located in other people."

And it certainly feels like we've tried it all — tough love, killing with kindness, indifference, group therapy, threats, and bribery to the point where we ourselves have been stretched to our upper limits.

Her behavior patterns are predictable

When you're close to someone with BPD, there seems to be a pattern of key behaviors that feel like points on a circular train track, which you'll perpetually visit again and again.

In my experience, the first behavioral stop on the BPD train tour is an amazing relationship. At her best, my sister can be abundantly caring, generous, and funny. When she's like this, she's my favorite person in the world, and I relish her joyful attention.

Unfortunately, I know now that our precious golden moments don't last for long — maybe a couple of hours minimum, and a few months at absolute maximum.

Usually there's an "incident" that will cause her to drop this pleasant facade she maintains, and I am left confused and hurt that perhaps she was only pretending to be friendly.

The "incident" could be her being caught out in a big lie, the discovery that she's stolen something from a family member (it happens more than you'd think), or her inability to contain an intense dark mood. 

The next stop is crashing self-destruction.

This is typically where her impulsive behavior kicks up a notch, or she at least doesn't seem to see the point in hiding it any more, because she thinks you'll hate her anyway.

At this stage, she cannot be reasoned with — for example, she once took a public bus somewhere on a whim, having no immune system from her chemo, even though she was constantly in and out of hospital with infections.

Becky will also shrug about stealing and selling our possessions, becoming more brazen in her blatant lies. She becomes obsessed with predatory, toxic people, continues to feed her spiraling debts with excessive spending, and lashes out at anyone who tries to constructively guide her. 

The next stop has become more common as she's gotten older. She'll pull away and distance herself by not responding to texts and calls, or back out of plans. I've learned to think this is likely rooted in the emotional instability of BPD sufferers, where she's so flooded with shame and intense self-dislike that she doesn't know how to dig herself out of the mess.

It could also be her choosing to abandon us first, before we "abandon" her. 

Our final destination is repentance. Becky is brilliant at saying sorry, but only when she's absolutely ready to do so.

Her apologies are the grand crescendos to the symphony of pain and misery her actions have put everyone who cares about her through once more. There are usually tears, essay-length WhatsApp messages, promises of giving therapy treatment another go, and her favorite catchphrase — "it's all in the past" — even if the past heartbreak she inflicted was only two hours prior.

Becky believes that by holding her hands up in admission and acceptance of her actions, her slate is wiped clean, and we should all draw a line under her throwing away my Christmas presents or flaking out on visiting our nana, who was grieving the loss of our granddad, to go do errands for a fairweather friend instead. 

My mother and I used to tightly cling to these big apologies as beacons of hope that maybe this time she'd actually mean it, as we unwittingly chugged back into the station from where we first started. 

Now, we know what to expect with her — and that's not to really expect anything at all. Still, though, we'd both be lying if we said there wasn't a teeny tiny part of us that had a flicker of optimism every time.

She doesn't have full control over her behavior

Kelly said that while there are negatives of labeling BPD as a disorder, there are also benefits. 

"One of them is that the person does not have full control over the way they're behaving, it's like they have blind spots, as we all do," Kelly said.

"What they're doing is partly automatic or learned behaviour. This is a pattern of behaviour that they're not thinking about or deciding to do. They're just doing."

The markers that we see from Becky can clearly be attributed to the four identifying BPD factors — emotional instability, disturbed patterns of thinking or perception, impulsive behavior, and intense but unstable relationships.

The disorder doesn't cause the person with it to lie, for example — the lying is a symptom to cover up whatever impulsive behavior they are intensely ashamed of.

While we have grown to understand her behavior, however, it hasn't gotten any easier with time.

"The fact this is labeled a disorder allows us to understand it is not all deliberation, there is a certain element that is controllable, and it can be changed of course over time," Kelly said. "But a lot of this is automatic behaviour or learned behaviour that needs to be unlearned, which takes a while."

Treatment is not always straightforward

BPD can be managed with therapy treatment, and Cognitive Behavioral Therapy (CBT) is normally the initial port of call. The aim is to restructure the way a person thinks or behaves.

The NHS website says it relies on the patient learning to understand and recognize their negative thoughts and actions, then drawing from strategies on how to respond in a positive way.

Becky has been offered CBT many times, but with each therapist, she flitted in and out of courses without putting in the work, or simply didn't show up. I don't blame them for dropping her as a patient — our health service is severely underfunded, and while you can lead the horse to water, you cannot make it drink.

The second course of action for treating BPD is Dialectical Behavioral Therapy (DBT) which is a form of CBT, but was specifically developed for people with this type of personality disorder. Again, it depends on effort from the patient, however the approach focuses on living in the present, tolerating distress, regulating emotions, and managing relationships with others. 

It's called "dialectical" because the therapy involves the two conflicting ideas of acceptance and change to improve BPD.

"In this condition, there's a tendency to take something to the limit sort of immediately," Kelly said. "For example, a dialectical behavioral therapist might give a person five emergency phone calls that they could make over the next two weeks. So when you're feeling bad, you make an emergency phone call to me, but you'll do it the five times and that's the limit. What the person with borderline personality disorder will do is they will make the five calls and immediately attempt a sixth."

He said DBT therapists offer extraordinary support with strict conditions attached, designed to address the issues those with BPD have in sticking to guidelines, but it's sometimes a difficult treatment to access.

Becky was put on the waiting list for this, too. However, she was going through the self-destructive point in her cycle when the opportunity to take part arose, and it passed her by — or so she says. She keeps changing her story.

Kelly told Insider that people with BPD do slowly see their behaviors calming down, and the greatest force for the symptoms gradually decreasing is a big life change in that person's world, alongside the accompanying therapy treatment.

"BPD does diminish over the years. But, it's a little bit like turning down the volume dial on a radio," he said.

"You can turn it down slowly, and often even if it's at the lowest point, you don't think you can hear anything, you think it's all gone, but if you put your ear up against it, there's still a bit there. You're looking for a percentage reduction in distressing symptoms. It does come and people do turn this around."

I've realized that while I love my sister, my own feelings are valid

No adult is responsible for the life of another adult, no matter how much you love them. EyeEm Premium via Getty

One of the biggest challenges I've faced while loving someone with BPD is controlling the devil and angel clashes in my own head. 

It's a scenario I can imagine anyone in the same situation identifying with — as much as you love them, part of you secretly despises them for actively turning their back on consistent treatment, and you want to throw your hands up and let them get on with it.

Over time, I've realized that while I support and love my sister, these feeling are valid — I'm only human, after all.

The negativity I feel towards my sister most of the time is heavily laced with guilt, too, as I know my frustration goes against what we are all told growing up about being understanding and tolerant when supporting those who struggle with mental illness.

On coping when someone close to you has BPD, Kelly said: "The first thing is to say is that no adult is responsible for the life of another adult.

"Some people feel entirely disproportionate guilt about how another adult is getting on with their life."

At times I've been mentally exhausted from continually mustering up the strength to be the bigger person and force myself to think about how hard it must be for Becky to live with a psychological disability. 

But Kelly said this is almost impossible for me, someone without BPD, to even begin to imagine. 

"If you don't have BPD, it's very difficult to understand the other person's perspective," he said. "Remember, you're doing this from the position of you being an emotionally well-regulated person and it is exceptionally difficult to imagine what it's like not to be an emotionally well-regulated person.

"It is almost impossible to understand how someone can wake up in the morning in a good mood and be engaging in suicidal actions by the mid-afternoon."

I'm learning how to adjust my approach

Becky's actions and words, driven by BPD, have become increasingly harder to swallow, but I've found strategies to fall back on.

For starters, safe spaces like Reddit's /BPDlovedones have provided a place where I can ease my festering guilt by reading posts from others in the same boat.

I also know I need to adjust my approach towards Becky.

"The best advice to family members is to consistently offer in low or medium level of support and availability at all times, good times and bad times, making no difference," Kelly said.

"In other words, not letting the crisis bump you too much from that position of offering a constant and low or medium level of support. The most harmful action is when there's no contact with the person except when there's a crisis, because that helps perpetuate a pattern."

In the past, I've often found myself shutting down to Becky, and constructing a gulf of silent hostility between us as a way to soothe the slashed open scars of previous damage. 

However, Kelly advised I try to adjust this knee-jerk reaction and avoid freezing Becky out of my life going forward. 

"It's very hard to do, because you're not going to get the same consistency or constancy from the other side," he added. "You're going to get nothing for weeks and months, and then something dramatic comes at you emotionally or a dramatic behaviour or some kind of crisis.

"But the key is to try and keep your side of the equation on as even a keel as possible, and as unaffected as possible by outside events."

After all, among the layered and knotty tangle of emotions I have towards Becky, there's an unchanging speck of hope at its core — I will always be on her team, even if she decides to set fire to the stadium.

There's no person in this world that can hurt me more than she can, but there is no person I would fight more viciously for.

Read more:

What to know about borderline personality disorder, the misunderstood mental illness that may affect nearly 6% of Americans

Why am I having weird dreams? The science behind your dreams and how to manage them

My boyfriend was diagnosed with bipolar disorder just after we started quarantining together — here's what I've learned so far

How to meditate: A guide to mindfulness meditation

A picture of a switch and lightbulb Sign up for notifications from Insider! Stay up to date with what you want to know. Subscribe to push notifications

ncG1vNJzZmivp6x7o8HSoqWeq6Oeu7S1w56pZ5ufony4tMCtZKKso2K5qrfEZquoZZykw6Z50qiknqeemnq4tdOhZJunopmys7jIp5xmqJWnwLC6wKWgrbFdmba0u9GdnKtlYmV%2FcXmT