Why People With Borderline Personality Disorder Tend to Lie

Borderline personality disorder (BPD) is a complex, multilayered condition that's as difficult to diagnose as it is to treat. One of its paradoxes involves lying. People with BPD fear abandonment and have trouble maintaining relationships. Nevertheless, they tend to lie, which ruins trust and intimacy, fosters resentment, and harms the very relationships they fear losing. Many family members and friends of those with BPD cite lying as a major problem in their relationships.

Is Lying a Symptom of BPD?

Despite its frequent occurrence with BPD, the Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR) does not list lying as a diagnostic criterion of BPD. That's partly because lying in BPD is generally not pathological; instead, it's a misguided attempt to avoid abandonment.

Paradoxically, the consequences of lying are particularly tough for a person with BPD. Lying harms the very relationships they fear losing. They tend to sabotage the relationships they desperately fear losing.

The Connection Between BPD and Lying

Lying, like other signs and symptoms of the condition, tends to occur because the person with BPD is unable to regulate their feelings and impulses. It's an act borne out of pain and fear. Often, people with BPD even believe their own lies.

Here are a few of the issues at the root of lying in BPD.

Intense Emotions

People with BPD experience intense emotions that they can't regulate; this often distorts their perceptions. They tend to view things through a strictly emotional lens that characterizes people and situations as either good or bad, with no middle ground.

They look for details that confirm what they feel and ignore those that don't. Either way, the result looks like deceit, and it can be very frustrating for friends and family members.

Impulsivity

BPD is also associated with impulsivity, the tendency to do things without thinking about the consequences. Sometimes, lying occurs when the person with BPD is just not thinking before responding.

Shame

People with BPD often experience deeply entrenched shame. Lying may be one way to conceal mistakes or weaknesses that involve feelings of shame and guilt.

Distorted Self-Perceptions

A person with BPD typically has an unstable self-identity. Sometimes, lies help them bridge the gap between their true identity and the one they've adopted for the time being.

Rejection Sensitivity

People with BPD are very sensitive to rejection. They may lie or exaggerate to cover mistakes or to maintain an overly positive image so that others will not reject them.

The Biology of Lying

Based on an imaging technique called functional magnetic resonance imaging (fMRI), researchers have found that deception is linked to the activation of the prefrontal cortex, which sits at the very front of the brain. The prefrontal cortex plays an important part in determining personality, planning cognitive tasks, and regulating social and emotional behavior. 

Interestingly, the prefrontal cortex is activated whether the deception is related to emotional or neutral deception (for example, lying about something to avoid a negative reaction versus lying about what you ate for breakfast). However, the basis of lying, such as whether the lie is meant to help or harm the person who is lying, may affect whether other regions of the brain are involved. 

Lying and Relationships

Whatever the reason for lying, it can be extremely detrimental to relationships of any kind. Often, friends and family members come to distrust the person with BPD and withdraw from them—precisely what the person with BPD typically fears most. Lying jeopardizes an essential support system and harms everyone involved.

Romantic Relationships

People with borderline personality disorder have difficulty maintaining relationships and tend toward quantity rather than quality. Nevertheless, a healthy, fulfilling romantic relationship with someone who has BPD is possible; in fact, some people are attracted to the emotionality, intensity, and excitement of such a relationship.

The key is knowing all you can about the disorder. Symptoms that can affect your relationship include impulsivity, lying, fear of abandonment, and instability. Your loved one may go from obsessively loving you (idealization) to seemingly hating you (devaluation) in a phenomenon known as splitting; this reflects the tendency to see people as all good or all bad. Couples counseling can help you navigate these issues together.

How to Cope With BPD and Lying

BPD and its associated behaviors, such as lying, can cause a great deal of stress. The first line of defense is information. Read all you can about the condition. Resources, both online and in print, abound. Find support groups, blogs, articles, and books. For example, the National Education Alliance for Borderline Personality Disorder offers a list of recommended books on BPD.

Try to address the root of the lying, not the lie itself. It likely stems from fear that you'll walk away from the person or think negatively of them. Reassuring the person that you will not abandon them may help.

When talking to a person with BPD, stay as calm and unemotional as you can. Address the lie directly with facts, not emotion.

Most importantly, seek support. Your loved one's lying, even though it's probably not malicious, can take a toll on your own mental health. Speak with a counselor, find support groups, and chat with the person's healthcare provider to find healthy ways to cope.

Is Treatment for BPD Effective?

Dialectical behavior therapy (DBT), a structured outpatient program developed by Marsha Linehan, PhD, and colleagues at the University of Washington, is considered the most effective treatment for BPD. Rather than making the person with BPD feel as though their emotions aren't valid or important, DBT teaches skills to help the person cope with them in healthy, productive ways.

Typically, DBT involves both group and individual therapy, sometimes along with phone or video coaching, and supplemented with reading materials and workbooks. The person with BPD monitors their own symptoms and skills application, and their coach tracks their progress.

Dialectical behavior therapy is based on the philosophy of dialectics, which maintains that nothing is all bad or all good, and openness to ideas other than your own is important.

Final Thoughts

Maintaining a relationship with a friend or family member with BPD can be difficult. However, it's important to understand that people with BPD often engage in destructive behaviors not because they intend to hurt you but because their suffering is so intense that they feel they have no other way to survive.

Lying may be one example of this. Although the reasons don't excuse the behavior, understanding the causes can help you cope when your friend or family member with BPD lies. In turn, it may help you move the person toward appropriate therapy.