Borderline Personality Disorder and Cheating

Being in a relationship with someone with borderline personality disorder (BPD) can be overwhelming and frustrating. Every relationship has its ups and downs, but BPD symptoms can make typical relationship problems such as cheating and accusations of infidelity worse. Nevertheless, many people have strong relationships with someone who has BPD.

BPD Features and Cheating

Some people believe BPD is associated with infidelity. Research has yet to show a direct connection between BPD and an increased likelihood of cheating. Rather, a hallmark feature of borderline personality—impulsive behavior—sometimes manifests as sexual preoccupation, early sexual exposure, casual sexual relationships, and promiscuity.

Likewise, a person with BPD is more likely to have been sexually abused or otherwise victimized. These issues can make cheating more likely in some people. BPD affects everyone differently, however; not all people with BPD cheat. But having unstable personal relationships is a hallmark symptom of this condition.

Why BPD Causes Trust Issues

One of the symptoms of BPD is the assumption that others are going to cause hurt. Whether or not people with BPD have the same likelihood of cheating as others, they are more likely to suspect their partners are cheating.

Because of low self-esteem, people with BPD have difficulty believing that someone could love them and remain faithful to them. As such, they are more likely to assume that their partners will cause them pain in some way. They also have difficulty considering "benign explanations" of their partners’ behavior.

Research also shows that people with BPD have difficulty maintaining cooperation with a partner. Their lack of trust is triggered when they feel rejected by another person or when their expectations are disappointed.

Also, because of the overwhelming fear of abandonment that's a hallmark trait of BPD, people with this condition tend to be more suspicious and distrustful, assuming or even truly believing that their partners are cheating. In turn, this negatively affects their relationships.

What to Do When Your Partner Has BPD

BPD can strain a relationship for both people involved. However, a combination of strategies can help if your partner has BPD (or if you suspect they do).

The first step is encouraging your partner to seek help, if they have not yet done so. Therapies, both psychological and medical, have evolved well past the days when BPD was thought to be incurable. Psychotherapy—particularly dialectical behavior therapy (DBT)— is believed to be the most effective treatment for BPD.

Couples therapy—especially if your partner resists individual treatment for BPD—can help you both work through relationship issues and understand where your partner is coming from. Through your sessions, you'll learn essential communication skills that can help you through tough times and strengthen your relationship. 

A Word From Verywell

People with borderline personality disorder fear abandonment and suffer from insecurity. As a result, their relationships are often marked by difficulty. However, help is available. Psychotherapy—particularly, dialectical behavior therapy—can help your partner develop coping strategies. Likewise, couples counseling can help you learn about BPD's effects on your relationship and how to handle the resulting challenges.