Unless a loved one or you yourself have been diagnosed with the disorder, you may not be familiar with borderline personality disorder (BPD). “BPD is a psychiatric illness that is defined by emotional dysregulation. People with BPD have problems that stem from a difficulty controlling their emotions, leading to problems with impulsivity, suicidal behavior, expressions of anger, and relationship problems,” says?Adam Carmel, PhD, a clinical professor of psychiatry and behavioral sciences at the University of Washington School of Medicine in Seattle.
It’s estimated that at least 1.4 percent of adults in the United States have BPD, but the rate may be higher due to misdiagnosis, according to the National Alliance on Mental Illness (NAMI). While it’s often reported that women suffer more than men — and as many as three-quarters of those diagnosed may be female — both women and men may have the disorder in equal numbers. (1)
Because BPD is a personality disorder, it will likely impact many areas of a person’s life, from their romantic relationships to friendships and their work life. It’s also common for someone with BPD to have co-occurring conditions like eating disorders, alcohol misuse, anxiety disorders, bipolar disorder, and post-traumatic stress disorder (PTSD). (2)
Most often, BPD is detected as early as age 12, says Jeff Riggenbach, PhD, a personality disorder expert and the author of Borderline Personality Disorder Toolbox: A Practical Evidence-Based Guide to Regulating Intense Emotions. He says that signs of BPD may show up between ages 15 to 18 in most people. But that doesn’t mean only adolescents are receiving treatment for the disorder. BPD may be something adults have struggled with for years prior to receiving the proper diagnosis.
Telltale Signs and Symptoms of Borderline Personality Disorder
NAMI lists the following as symptoms of BPD, according to The Diagnostic and Statistical Manual of Mental Disorders, which clinicians rely on for diagnosis. These symptoms have to cause significant problems in someone’s life: (1)
- Frantic efforts to avoid real or imagined abandonment by friends and family.
- Unstable personal relationships that alternate between idealization (“I’m so in love!”) and devaluation (“I hate her”). This is also sometimes known as “splitting.”
- Distorted and unstable self-image, which affects moods, values, opinions, goals, and relationships.
- Impulsive behaviors that can have dangerous outcomes, such as excessive spending, unsafe sex, substance abuse, or reckless driving.
- Self-harming behavior including suicidal threats or attempts.
- Periods of intense depressed mood, irritability, or anxiety lasting a few hours to a few days.
- Chronic feelings of boredom or emptiness.
- Inappropriate, intense, or uncontrollable anger — often followed by shame and guilt.
- Dissociative feelings — disconnecting from your thoughts or sense of identity or “out of body” type of feelings — and stress-related?paranoid thoughts. Severe cases of stress can also lead to brief psychotic episodes.
“A lot of people have traits of BPD, but to get a diagnosis, it’s complex. These things need to be a pervasive pattern that impacts every aspect of their life. They’re also often in and out of the [psychiatric] hospital,” says Jill Weber, PhD, a psychologist in private practice in the Washington, DC, area.
That said, just because someone recognizes themselves in a couple of points on this list doesn’t mean they should self-diagnose with BPD. ?“If someone self-injures, it doesn’t mean it’s BPD; if they feel emotional when left or abandoned, it doesn’t mean it’s BPD,” she adds.
The Suspected Causes and Risk Factors of Borderline Personality Disorder
As with many other conditions, it’s not just one thing that causes BPD. “We see BPD as a transaction between nature and nurture,” says Dr. Carmel. So while there are three main causes — genes, brain abnormalities, and environmental factors — they all play into each other in the development of BPD. Here’s a closer look at each of them.
Genetics?A person’s genetics are a big factor in whether he or she experiences BPD.?“Studies show anywhere from 49 to 65 percent of the development of BPD is genetic in nature,” says Dr. Riggenbach. Just two or three decades ago, experts believed that the cause was a bad childhood (something that is in part valid today, but that doesn’t account entirely for the disorder’s development). “Parenting can certainly contribute, but genetic underpinnings are stronger than people realize,” he says.
Everyone is born different — that’s obvious. “It’s not like you’re born predisposed to BPD or not; we’re likely all born somewhere on the continuum,” says Riggenbach. Still, some people are born with more sensitive or emotionally vulnerable dispositions. These people may feel emotions more strongly than others, notes Carmel. Still, just because someone is “sensitive” doesn’t mean they’ll develop BPD, he adds. The environment comes into play, too.
Brain Abnormalities?There may also be unique characteristics in someone’s brain with BPD. “Researchers have found particular brain activity that affects people’s ability to cooperate, which can lead to unstable relationships and erratic behaviors. In essence, people with BPD have parts of their brain that respond differently to emotional situations than other people,” says Gladys Frankel, PhD, a clinical psychologist based in New York City.
This knowledge is based on a 2008 study funded by the National Institute of Mental Health that found that people with BPD displayed less trust and cooperation when playing a game with a partner without BPD. They were also less likely to try to repair their relationship. (3)
This interplay happens between the amygdala (the emotional hub of the brain) and the frontal lobes (which regulate judgment). In those with BPD, their fear response becomes overactivated, while the part that controls judgment stays underactivated, Dr. Frankel explains. Their brains are wired to respond differently — and often out of the social norm — compared with those without BPD.
What’s more, research from India has found that those with BPD have an impaired ability to recognize facial expressions on others, which may also contribute to social and relationship problems. (4)
But whether people with BPD are born with different brains or these changes are the result of the disorder isn’t clear. (5) “No one is doing MRIs of little children to see how their brain is activating,” says Dr. Frankel. But she notes that growing up in a dysfunctional family where someone doesn’t learn how to manage his or her moods will reinforce these brain patterns.
Environmental Factors?Experts consider the tipping point for BPD to be what’s called an “invalidating environment.” This is defined when “someone’s private experience is ignored or punished,” says Carmel. One example: The person cries at a scene in a movie, and friends and family may look at them and say, “What are you crying about? I don’t see what the big deal is,” he explains. They may feel like they grew up with constant judgment and dismissal.
Of course, rolling your eyes when someone tears up at a sappy commercial on TV won’t “give” someone BPD. But a chronically invalidating environment can be a contributing factor.
Sometimes a family under some type of strain becomes annoyed by a particularly sensitive child. “It’s a lack of emotional awareness,” says Dr. Weber. The child may say they’re hungry only to be told they’re not. Or the child may express that they’re upset about something at school, and the parents may respond that they should shut up and get over it, she explains. “The sensitive child begins to feel bad about himself and may feel sick, mentally ill, or incompetent,” Weber says. As they grow up, they become very self-critical and explore ways to cope, and that’s when maladaptive behaviors like eating disorders or self-injury can surface.
The ultimate example of an invalidating environment takes shape as traumatic experiences, including abuse, sexual abuse, and abandonment, typically during early childhood. When someone goes through these things, their needs and safety are being ignored, says Weber. “The people around them aren’t protecting them,” she says. These more severe situations are typically described as the trigger point in the development of BPD. (5)
That said, someone’s environment may also respond — and thus reward — emotionally escalated behavior, which can reinforce problems, says Carmel. “I’ve had a client say that the only time her parents said they loved her was when she was in a hospital bed following a suicide attempt,” he explains. “If someone is struggling for help, it can take an escalated crisis behavior to elicit that response of nurture and support.”
Know That No One Is Destined to Develop Borderline Personality Disorder
Even if you don’t have the genetic makeup that makes you more susceptible to BPD, you can still develop it within the context of an extremely invalidating family system, says Weber. Likewise, there are people who are naturally extremely sensitive and don’t have BPD. It’s all about the interaction of genes, brain activity, and one’s environment.
Editorial Sources and Fact-Checking
- Borderline Personality Disorder. National Alliance on Mental Illness. December 2017.
- Borderline Personality Disorder: Symptoms and Causes. Mayo Clinic. July 17, 2019.
- King-Casas B, Sharp C, Lomax-Bream L, et al. The Rupture and Repair of Cooperation in Borderline Personality Disorder. Science. August 8, 2008.
- Anupama V, Bhola P, Thirthalli J, Mehta UM. Pattern of Social Cognition Deficits in Individuals With Borderline Personality Disorder. Asian Journal of Psychiatry. March 2018.
- Borderline Personality Disorder. National Institute of Mental Health. April 2022.