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Borderline Personality Disorder or a Mercurial Disposition?

Mood swings may be normal, but explosive anger and irrational behaviors are not.

Key points

  • BPD is treatable, but the person diagnosed with the disorder must be committed to change for treatment to work.
  • Fear of abandonment is strong, but behaviors that are exhibited by someone with BPD often drive away partners or family members.
  • Mindfulness training, as part of Dialectical Behavior Therapy, can help ground a person with BPD when their emotions feel overwhelming.

When people hear the term "Borderline Personality Disorder (BPD)," they may imagine that it means someone is “on the borderline” between possessing a normal and an abnormal personality. However, the term originally was coined to describe the bordering edge between psychosis and neurosis.

Individuals who are suffering from psychosis are unable to distinguish reality from hallucinations or delusions, maintain a stable sense of self, or practice healthy defense strategies or coping methods in the face of challenges. With neuroses, a person recognizes that they are struggling with some aspect of functioning, but they are in touch with reality. However, individuals with BPD fall somewhere between these two areas of compromised functioning as they display symptoms of neuroses, but struggle with maintaining a realistic perspective on people and events in their lives.

At some point, any of us may struggle with feelings of anxiety or depression, have doubts about our efficacy or self-worth, or experience relationship conflicts. Few of us go through life without experiencing a few emotional downturns, but we also recognize that we need to regulate these feelings and focus on moving forward — on our own or with the help of a counselor. Unfortunately, individuals with BPD are often unable to “pick themselves up and shake themselves off” when they experience these feelings and may become mired in chronic feelings of helplessness and irrational anger, engage in efforts to avoid abandonment while simultaneously engaging in behaviors that actually ruin relationships and, therefore, lead to abandonment, and display impulsive behavior that can do lasting harm to themselves or others.

Whether the threat of rejection or a disagreement is real or merely perceived, individuals with BPD can display unbridled, explosive anger, fears that resemble paranoia, and impulsive behaviors that may yield lasting consequences. For the person with BPD, these behaviors all make logical sense as appropriate reactions to their misperceived understanding of a situation. Stress exacerbates the symptoms of BPD, but the consequences of the BPD-associated behaviors generate even more stress, which can lead to further spiraling for the sufferer.

Kaleidoscope Perspectives

In the murky middle ground between psychosis and neurosis is where BPD is located, because individuals who suffer from this disorder tend to have a clear grasp on reality but are unable to maintain secure relationships with others due to their fragmented sense of self and others. They have a hard time distinguishing between what they “think” someone meant by their actions or words and what the other person’s true motivations actually were.

This kaleidoscope-like perspective leads them to swing between extremes in their evaluations of others and experience “love’em until they hate’em” relationships with others. Individuals who have been diagnosed with BPD may make wild assumptions about another’s intentions and be firmly resistant to listening to another’s perspective or taking time to imagine another side to the story. And just as a person turns the kaleidoscope and changes the image, individuals with BPD can change their feelings about someone just as easily and completely.

While some of us may “blow hot and cold” on occasion, people with BPD tend to have a history of failed relationships due to paranoia-tinged judgments about the behavior or feelings of others. Another marker of this disorder is impulsivity; while some of us like to do things on a whim, individuals with BPD can display exceptionally impulsive behaviors and responses to others. If they’re angry with someone, they may lash out in inappropriate ways. When we’re disappointed in ourselves, some of us may mentally berate ourselves and our self-esteem may take a hit. Individuals with BPD may engage in self-harming behavior when they make a mistake or let someone down.

All or Nothing Thinking Breaks Bonds

Ironically enough, individuals who are diagnosed with BPD actually have a very difficult time accepting that everyone exists in that “middle ground” between the extremes of “all good” and “all bad.” They have a hard time thinking beyond a “black and white” construct of behavior or motivation. Adding to this risk is that someone with BPD often misperceives the other’s intentions, thoughts, or actions. They shift the kaleidoscope, their prior beliefs fall away, and new, misguided beliefs may take shape. If they, or someone they know, does a single “bad” thing, they perceive themselves or that person as “all bad,” even if that person was perceived as “all good” just moments before.

Enduring relationships can be a struggle for those with BPD as the “all or nothing/good or bad” categorization can be hurtful to family and friends who are overwhelmed by the effort to ride the crest of such emotional extremes in a primary relationship. Being the object of affection and appreciation may feel good in the moment, but there is always the chance that one wrong move can cast you into the role of adversary and villain with no warning. This can take a toll that chips away at one’s wellbeing and sense of self.

The unpredictability of the beliefs and behaviors of someone with BPD can be exhausting for family, co-workers, and friends. The fear of “doing the wrong thing” can be paralyzing, as no one wants to rock the boat when the water is calm. These symptoms of emotional dysregulation and impulsivity (Euler et al., 2021) have been identified as key foci for treatment as these two symptoms contribute to the inability to maintain healthy relationships. And without healthy relationships, wellbeing will suffer even more. Thus, treatment is essential to optimal health.

Maintaining Relationships with Individuals with BPD

Emotional dysregulation, paranoia, and impulsive behaviors, all symptoms of BPD, are likely to push away others. If you’re trying to maintain a relationship with someone with BPD, you will need to create and enforce firm boundaries. You will need to protect your own self-interest and refuse to be pulled into feelings or activities that don’t serve you. When a partner goes ballistic about an imagined wrong, don’t allow yourself to be pulled into their drama. Steer clear of topics or places that are likely to create contention. Knowing the triggers is helpful, but also remember that triggers can change.

Maintain consistency in your relationship and do what you can to support emotion regulation and acknowledge the times when they are able to maintain their sense of equilibrium and stay in the present moment rather than going over-the-edge in paranoid imaginings of others’ behavior. Focus on spending time together in activities that are pleasure-giving, not angst-stirring. Recognizing signs that a mood swing is building can help you manage your own reactions and help your partner to manage their own. While predictability may seem boring, that may be the best way to help someone you love who has BPD manage their lives and their relationships.

Warning Signs of Relationship Danger

Your safety should be your primary priority. If a person becomes violent, exit the surroundings immediately and reach out for assistance if self-harm is being threatened. If needed, exit the relationship, if the person refuses to seek treatment for diagnosed BPD. If you are spending too much time avoiding topics, activities, or people because they are “hot spots” that build into conflagrations, take stock of the value of the relationship, and assess whether it is worth the effort it requires to maintain. If you find yourself avoiding spending time with this person or if you are always dreading being around them, this is a warning sign that the relationship is costing more to your wellbeing than its benefits are worth.


BPD behaviors typically emerge during late adolescence and young adulthood, and getting into treatment early can change the course the disorder takes. While research also suggests that the symptoms of BPD begin to wane over time, usually in the 30s and 40s, if you care for someone who suffers from this disorder, “waiting it out” is not advised. Untreated BPD can be a risk to wellbeing in a variety of ways including self-harm and personal violence, but treatment through Dialectical Behavior Therapy (DBT), Cognitive Behavioral Therapy (CBT), and psychotropic medications can make a world of difference in quality of life for the person who suffers from BPD and all those who care for and about this person.


Euler, S., Nolte, T., Constantinou, M., Griem, J., Montague, P. R., Fonagy, P., & Personality and Mood Disorders Research Network. (2021). Interpersonal problems in borderline personality disorder: associations with mentalizing, emotion regulation, and impulsiveness. Journal of personality disorders, 35(2), 177-193.

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