BPD and Lying in Relationships: How to Build Trust 

Why Do People with BPD Lie? 

What is the connection between BPD and lying? If you’ve ever been lied to, you know how painful it can be, especially if someone you care about hasn’t been truthful with you.  

However, first we must understand the disordered mental state of a person with BPD and how it may compel them to lie within the context of a relationship. People with borderline personality disorder don’t lie out of malice or to deliberately manipulate or deceive. Though it may seem counterintuitive, pathological lying is a coping mechanism — a way to avoid or deflect their deep-seated emotional struggles.  

Fear of Abandonment 

“Lying in BPD is generally not pathological,” writes Dr. Kristalyn Salters-Pedneault, a clinical psychologist. “Instead, it’s a misguided attempt to avoid abandonment.” 

A person with BPD bases a great deal of their own identity on their relationship. The idea of being left alone can be unbearable to them — but they can react with anger or hostility if they believe (however incorrectly) that their partner is abandoning or neglecting them. Driven by a desperate need to avoid being rejected, they might fabricate stories to keep them from leaving.  

To an outsider or their partner, this may seem like an intentional effort to hurt, but in reality, it’s their way of trying, in vain, to keep the relationship intact — even if it wasn’t in danger to begin with. 

Emotional Dysregulation  

People with BPD often experience intense emotions and their subsequent emotional responses, which can distort how they perceive situations, leading them to interpret interactions and events through emotion rather than logic. Emotional dysregulation means they will see people and events only in black-and-white extremes — either completely good or entirely bad — with no room for subtlety. 

In these moments, they may focus and zero in only on aspects that support their current mood while overlooking conflicting details. It’s a type of BPD bias that may look like lying or manipulation, but for someone with BPD, it may feel like the truth in the moment. 

Low Self-Esteem 

A deep sense of inadequacy, shame or guilt can make honesty feel like a risky venture. When someone with BPD believes they aren’t good enough or have a negative opinion of themselves, they may say what they want others to hear, like embellishing details or fabricating stories.  

This symptom of BPD is also not intentional — the person doesn’t set out to deliberately deceive. Like substance abuse as a coping mechanism, it’s an unhealthy way to secure love and approval. But when it becomes chronic, one’s significant other doesn’t know if they’re telling the truth, creating distrust and disconnect in a relationship. 

Struggles with Identity  

We all have moments in life when we question who we are and what our goals, values, and identity represent. But people with BPD are prone to quickly vacillating and shifting their sense of self, never clear on who they are, what they want or what they believe. 

“They may … abruptly and dramatically change their self-image, shown by suddenly changing their goals, opinions, careers or friends,” notes the Cleveland Clinic. “They also tend to sabotage their own progress. For instance, they may fail a test on purpose, ruin relationships or get fired from a job.”  

Here, people with BPD lie as a tool to experiment with different personas in an effort to find one that feels acceptable. This impulsive behavior and ever-changing self-presentation can further complicate relationships and become challenging for loved ones to know who you truly are. 

How Does Lying Harm Relationships?  

Even if lying is not malicious, it still has consequences. In relationships, dishonesty creates fractures that can undermine trust, emotional bonds, and your future together. “In an intimate relationship, emotional honesty includes allowing our partner to know who we are,” says relationship and codependency expert Darlene Lancer. “Honesty is more than simply not lying.”  

Eroding Trust 

Trust is the foundation of any relationship. What does a relationship stand on when partners hide things from each other? Dishonesty — intentional or not — can weaken that foundation. A partner may start questioning what is real and what isn’t, leading to doubt, insecurity, and second-guessing even in ordinary conversations. 

Over time, this erosion of trust can make genuine moments of honesty feel meaningless. Even when a person with BPD is telling the truth, it invites a constant sense of skepticism into the relationship where their partner may be inclined to disbelieve everything they may say. Rebuilding that trust takes cooperation and work on behalf of both partners. 

Increased Conflicts 

“A hallmark of BPD is heightened emotional sensitivity, which can lead to personalizing everyday interactions and conflicts. This often results in misunderstandings, unresolved conflicts and feelings of hurt for both partners,” notes Forbes. Dishonesty in a relationship can exacerbate these outcomes, escalating into arguments or disputes between partners. 

When you repeatedly encounter destructive behaviors, such as lying (even if unintentionally from a person with BPD), it can trigger a cycle of anger and defensive responses, straining any hope of fostering good communication. A small disagreement can spiral into a full-blown argument, with both partners feeling unheard and hurt.  

Emotional Exhaustion 

Chronic lying in a relationship can leave partners emotionally taxed and able to handle only so much before giving up on the relationship. This exhaustion can lead to resentment, detachment or even burnout, making it harder to maintain a strong emotional connection — where a relationship becomes more about survival than sharing a synchronistic, genuine connection. 

It can become further complicated in a relationship with a person with BPD, especially if lying and distrust are involved. They may feel overwhelmed by guilt, fear of abandonment or the pressure to maintain a specific image. Meanwhile, their partner may feel emotionally depleted from trying to decipher what’s true and what’s not.