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Intense and Emotional: Writing About Borderline Personality Disorder

We all go through periods when our emotions feel raw—but for people with borderline personality disorder, this rawness doesn’t just fade away with time.

Their emotions continue to be sensitive, like a badly healed cut, which can open avenues for all kinds of conflict in a story.

In How to Tell If Your Character Has Borderline Personality Disorder, we covered the features of BPD and the behaviours someone must show to be diagnosed with this personality disorder. Today let’s take a closer look at the diagnosis criteria and see how they can be incorporated into your stories.

To Keep in Mind:

The information in this post comes from the DSM-5 (see ‘Further Reading’). Please do not use it to diagnose yourself or others. It isn’t intended to be a substitute for professional advice so do consult a qualified clinical professional if you have any questions about the diagnosis criteria. Feel free to use this information to diagnose your characters, however!


When writing about characters with borderline personality disorder, it may help to think of a time when you felt particularly emotionally vulnerable or on-edge. Maybe it was during a stressful period, during your teenage years, or after a traumatic event. Did you feel like your emotions were close to the surface, easily sparked? Think about what it would be like to feel this way all the time. You may be able to understand your BPD character a little better now as we go through the diagnosis criteria.

Remember: your character needs to display at least five (or more) of the following criteria, over a long period of time, to be diagnosed with borderline personality disorder. If they don’t show at least five of these behaviours, they may have borderline traits, but not the disorder itself.

With that in mind, let’s take a look at the list of behaviours characteristic of someone with a borderline personality disorder.

Criterion 1:
Repeatedly self-harming (e.g., cutting or burning), making suicide threats, or attempting suicide.

Self-harming doesn’t mean your character is trying to commit suicide; rather, it could be a way to release the emotional pain or sense of emptiness bottled up inside. Many people with BPD are highly sensitive to emotion, which, combined with often traumatic, abusive or invalidating backgrounds, can make emotions overwhelming. Your character may try to relieve this pressure through self-harming.

People with BPD often have an intense fear of abandonment or rejection. If someone tries to leave your character—for example, through breaking up with them—or set boundaries or remove a structure they’ve become dependent on, they may make suicide threats or actual attempts to prevent this.

Criterion 2:
Acting impulsively in two potentially damaging areas, not including self-harm or suicide attempts (e.g., drug abuse, unsafe sex, dangerous driving, reckless spending).

The key thing here is impulsivity. Your character doesn’t plan to do these potentially dangerous things. It’s a spur of the moment decision that could take them—and your readers—by surprise. It’s often undeniable too, as though they can’t stop themselves.

Your character might binge eat, spend money compulsively, shoplift, drink excessively, drive recklessly, use drugs, or engage in other equally damaging activities on impulse. Each has its own consequences, some more serious than others, which can cause problems aplenty in your story.

Criterion 3:
Having intense and unstable relationships that swing between idealisation (i.e., believing the person and relationship are perfect and loving them deeply) and devaluation (i.e., believing they are awful and hating them).

Fear of abandonment and a feeling of emptiness could make your BPD character very clingy. When your character loves someone, they see them as perfect, flawless, incapable of doing wrong.

That intense love can turn to hatred in an instant, though, if something happens to change your character’s mind. It could be something as small as a character attempting to go home after visiting, as in the film Gia, resulting in an explosion of anger or despair.

Criterion 4:
Feeling intensely afraid of abandonment and making frantic efforts to prevent this, not including self-harm or suicide attempts (e.g., constantly calling or texting someone, clinging to someone and refusing to release them).

This fear of abandonment could lead to your character going to drastic lengths to keep someone in their life. What kind of strain would it put on their relationships if your character tried to be with someone constantly? Would they find it suffocating and attempt to leave, and what escalations in your BPD character’s behaviour might this cause?

Criterion 5:
Having an unstable self-image and no strong sense of self.

Your character may have no clear idea of who they are—their personality, their beliefs, their identity—leaving them feeling hollow. To compensate, they might imitate and adopt the traits of others. How might your other characters react if your BPD character took on their likes and dislikes, their beliefs and goals? What kind of problems could this cause?

Criterion 6:
Feeling empty, worthless or lonely over long periods of time.

If your character had an invalidating childhood—in other words, their emotions were dismissed, ignored or responded to inappropriately and inconsistently—their sense of worth may have plummeted. This feeling of emptiness and loneliness is deep-seated, like a piece of themselves is missing, and can leave them feeling vulnerable.

Criterion 7:
Experiencing severe mood swings, which can last anywhere from hours to days (e.g., feeling irritable, depressed or anxious).

Imagine your character’s emotional nerves are exposed, at the surface of their skin. Small triggers, sometimes unknown to the character themselves, can set those nerves afire. Their emotional outbursts aren’t a ploy for attention, as may be the case with someone with histrionic personality disorder, but a genuine display of overwhelming emotion.

These mood swings are extreme and sudden—small triggers in a scene could change your character’s mood from happiness to fury in a blink—and these volatile emotions often take a long time to settle back down again.

Criterion 8:
Feeling sudden, intense and often uncontrollable anger or aggression, which can lead to loss of temper or physical fights, or showing this anger in inappropriate ways or situations.

Because those emotional nerves are exposed, any real or imagined insults directed towards your character could spark rage, manifesting in explosive displays of anger or physical fights. Emotional reactions are intensified, so situations that might cause any other character frustration could result in fits of screaming or inappropriate aggression for your BPD character.

Causing fights could also be another way for your character to express their self-destructive tendencies. Being hurt by another could even be their goal—a way to release emotional pain or help them with their self-destruction.

Criterion 9:
Feeling paranoid or disconnected from the world, your body, thoughts or behaviour when stressed.

Paranoia. It could be your character’s family, friends, strangers on the street—are they talking about your character behind their back? When they laugh, is it directed at your character? What about all that whispering? It’s about your character, isn’t it?

Paranoid thoughts can infect all areas of your character’s life and distort their thinking. Despite periods of hating family and friends, despising them for their perceived slights, your character might cling to them, fearing abandonment.

This mix of paranoia, loathing and loving doesn’t just affect your BPD character, however—think about how it might strain their relationships with those around them. Do family and friends leave them? How might this heighten your character’s fear of abandonment?

Another feature of this part of the diagnosis criteria is dissociation, or feeling disconnected from yourself or your surroundings, when stressed. Your character might have whole episodes that they can’t remember because of a dissociative experience. This could make them an unreliable narrator, perfect for conflict and mystery creation.

(You can find out more about dissociative amnesia in I Forget… What Can Cause My Characters Amnesia?)