Borderline Personality Disorder: Symptoms, Causes, and Treatment
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: What is borderline personality disorder?
Borderline personality disorder is a mental health condition affecting emotions, self-image and relationships; it is not a character flaw or a choice. Signs include fear of abandonment, unstable relationships, mood swings, impulsiveness and threats of self-harm. Talk therapy, especially dialectical behavior therapy (DBT) and CBT, is the main treatment, and most people improve greatly over time.
What the research says
DBT eased depression and anger in adults with BPD. A meta-analysis of 7 controlled trials found a moderate reduction in depression after standard DBT (SMD −0.59, 95% CI −1.02 to −0.16) and in anger expression (SMD −0.738, 95% CI −1.371 to −0.104). The authors noted high heterogeneity and limited trial numbers (Li and Mao, Psychiatry Res, 2026) [7].
Stand-alone DBT skills groups showed large symptom reductions with acceptable retention. In a review of 7 studies (5 in the meta-analysis), BPD severity improved substantially within groups (−1.32, 95% CI −1.99 to −0.64). Pooled dropout was 29%, meaning 71% stayed in treatment (Arqueros et al., Personal Disord, 2026) [8].
For adolescents, benefits were real but small. A meta-analysis of 12 randomized trials with 844 adolescents found small effects on BPD symptoms (SMD −0.27, 95% CI −0.47 to −0.06) and emotion regulation (SMD −0.26). No significant effects were seen for depressive symptoms or quality of life, and gains appeared to erode over 12 to 36 months (Cai et al., Front Psychiatry, 2026) [9].
Study details are from PubMed abstracts.
What does borderline personality disorder actually mean?
Borderline personality disorder is a mental health condition that affects the way people feel about themselves and others, making it hard to function in everyday life. Three patterns define it: unstable and intense relationships, impulsiveness, and an unhealthy way of seeing oneself.
Impulsiveness here means having extreme emotions and acting on them without thinking things through first. Underlying all three patterns is a strong fear of abandonment. Even though people with BPD deeply want loving, lasting relationships, that fear of being left alone often sets off mood swings, anger, impulsiveness, and self-injury. These can end up pushing people away, creating the very loneliness they fear.
The condition usually begins by early adulthood and is most serious in young adulthood. There is real hope in that trajectory: mood swings, anger, and impulsiveness often get better with age. The deeper struggles with self-image, fear of abandonment, and relationships may continue longer, but with treatment many people learn to live stabler, more fulfilling lives.
What are the nine signs of borderline personality disorder?
Borderline personality disorder affects how you feel about yourself, how you relate to others, and how you behave. The signs tend to show up as a pattern rather than isolated moments.
Symptom | What it looks like in everyday life |
Strong fear of abandonment | Going to extreme measures to avoid separation or rejection, even when the fears are made up |
Unstable, intense relationships | Believing someone is perfect one moment, then suddenly believing the person doesn't care enough or is cruel |
Rapidly shifting self-image | Sudden changes in goals and values; seeing yourself as bad or as if you don't exist |
Stress-related paranoia | Periods of feeling paranoid or losing contact with reality, lasting minutes to hours |
Impulsive, risky behavior | Gambling, dangerous driving, unsafe sex, spending sprees, binge eating, drug misuse, or suddenly quitting a good job or ending a positive relationship |
Threats of suicide or self-injury | Often triggered by fears of separation or rejection |
Wide mood swings | Shifts lasting hours to days, from very happy to irritable, anxious, or ashamed |
Ongoing emptiness | A persistent feeling that something inside is hollow |
Intense, hard-to-control anger | Frequent temper loss, sarcasm or bitterness, or physical fighting |
One detail helps separate BPD from other mood conditions: the mood swings are short. They last from a few hours to a few days rather than the weeks or months typical of bipolar episodes.
What causes borderline personality disorder?
Like other mental health conditions, the causes of BPD aren't fully known. Experts point to a combination of environmental and biological factors rather than one single cause. A history of child abuse or neglect is a notable environmental link, and research connects the condition to genetics and to changes in the brain.
Possible cause | What the evidence shows |
Environmental factors | A history of child abuse or neglect is linked to the condition |
Genetics | Twin and family studies suggest personality disorders may be inherited or be strongly related to other mental health conditions among family members |
Brain changes | Research shows changes in certain areas of the brain affect emotions, impulsiveness, and aggression |
An important takeaway: BPD is not a choice, a weakness, or something caused by bad parenting alone. It emerges from the interaction of biology and life experience.
Who is at higher risk of borderline personality disorder?
Two kinds of risk factors stand out: things you're born with and things you go through.
Risk factor | Why it raises the risk |
Family history | You may be at higher risk if a blood relative (a mother, father, brother, or sister) has the same or a similar condition |
Stressful childhood | Many people with BPD report being sexually or physically abused or neglected as children |
Early loss or separation | Losing or being separated from a parent or close caregiver when young raises the risk |
Unstable home environment | Parents or caregivers with substance misuse or mental health issues, hostile conflict, or unstable family relationships |
What complications can untreated borderline personality disorder cause?
Left untreated, BPD can damage many areas of life, including close relationships, jobs, school, social activities, and how a person sees themselves. The consequences compound on each other.
Area of life | How it gets affected |
Work and school | Repeated job changes or losses; not finishing an education |
Legal life | Multiple legal issues, sometimes including jail time |
Relationships | Conflict-filled relationships, marital stress, divorce, or abusive relationships |
Physical safety | Self-injury such as cutting or burning; frequent hospital stays; unplanned pregnancies, sexually transmitted infections, motor vehicle accidents, and physical fights from impulsive behavior |
Life-threatening risk | Attempted suicide or death by suicide |
BPD also frequently travels with other mental health conditions, which is one reason treatment often needs to cover more than one problem at a time. These include depression, alcohol or other substance misuse, anxiety disorders, eating disorders, bipolar disorder, post-traumatic stress disorder (PTSD), attention-deficit/hyperactivity disorder (ADHD), and other personality disorders.
What should you do in a borderline personality disorder crisis?
If you have fantasies or mental images about hurting yourself, or thoughts about suicide, get help right away. In the U.S., call or text 988 to reach the Suicide & Crisis Lifeline, available 24 hours a day, seven days a week. The service is free and confidential. You can also use the Lifeline Chat at 988lifeline.org.
U.S. veterans and service members in crisis can call 988 and press 1 for the Veterans Crisis Line, text 838255, or chat online at veteranscrisisline.net. For help in Spanish, call 988 and press 2, or text AYUDA to 988. You can also call your local emergency number, contact your mental health professional or doctor, reach out to a trusted loved one, or contact someone from your faith community.
If you notice symptoms in a family member or friend, talk to that person about seeing a doctor or mental health professional. You can't force someone to change, but if the relationship is causing you a lot of stress, it may help to see a therapist yourself.
How is borderline personality disorder (BPD) diagnosed?
Borderline personality disorder has no blood test or brain scan, so a trained professional makes the diagnosis through conversation and careful evaluation.
Diagnostic step | What happens |
Detailed interview | A thorough conversation with your doctor or a mental health professional |
Mental health evaluation | A series of structured questions may be included |
Medical history and exam | To rule out physical causes and understand overall health |
Discussion of symptoms | A full look at how symptoms affect daily life |
One point families often ask about: a diagnosis of BPD is usually made in adults, not children or teenagers. Behaviors that look like BPD symptoms in young people may go away as they mature.
How is borderline personality disorder treated?
Borderline personality disorder is mainly treated with psychotherapy, also called talk therapy. Medicine may be added, and hospital stays may be recommended if safety is at risk. Treatment helps you learn skills to manage and cope with the condition, and it can also treat co-occurring problems like depression or substance misuse.
Talk therapy works on five goals:
Focusing on your ability to function.
Learning to manage emotions that feel uncomfortable.
Reducing impulsiveness by learning to notice feelings rather than act on them.
Improving relationships by becoming aware of your feelings and those of others.
Learning about the condition itself.
Good management often combines individual therapy, group therapy, family education, and medicines for related conditions.
The therapies that have been shown to work
Therapy | How it helps |
Dialectical behavior therapy (DBT) | Combines group and individual therapy built specifically for BPD; teaches skills to manage emotions, handle distress, and understand relationships better |
Cognitive behavioral therapy (CBT) | Helps you change beliefs that come from distorted ways of seeing things; reduces mood swings and anxiety and makes self-harm and suicide attempts less likely |
Schema-focused therapy | Focuses on changing negative thought patterns |
Mentalization-based therapy (MBT) | Helps you notice your thoughts and feelings, see things differently, and think before reacting |
STEPPS (Systems Training for Emotional Predictability and Problem-Solving) | A 20-week group program that includes family members, caregivers, friends, or partners; used alongside other talk therapy |
Transference-focused psychotherapy (TFP) | Uses the relationship with your therapist to learn about emotions and issues with others, then applies those lessons elsewhere |
The role of medicines
No medication has been approved specifically to treat BPD. However, some medicines can ease symptoms, and others treat conditions that travel with BPD, such as depression, impulsiveness, aggression, or anxiety. These include antidepressants, antipsychotics, and mood-stabilizing drugs. Always discuss the benefits and side effects of any medicine with your doctor or mental health professional.
When hospitalization helps
At times, treatment in a psychiatric hospital or clinic may be needed. Staying in the hospital can keep you safe from harming yourself and create a protected space to talk through suicidal thoughts or behaviors.
Recovery takes time
Learning to manage emotions, thoughts, and behaviors takes time. Most people improve greatly, though some always struggle with some symptoms. You may have periods when symptoms are better and periods when they're worse. That's part of the journey, not a sign of failure. Your chances of success are best when you work with a mental health professional who has experience treating BPD.
How can people cope with borderline personality disorder at home?
Professional treatment does the heavy lifting, but daily habits shape how well it works.
Learn about the condition so you understand its causes and treatments.
Notice what makes you angry or impulsive, and stick to your treatment plan. Attend all therapy sessions and take medicines as directed.
Work with your professional to build a written plan for what to do the next time a crisis hits.
Stay away from drugs and alcohol, which sharpen impulsiveness.
Consider involving the people close to you in your treatment so they understand how to support you.
Manage strong emotions with coping skills like breathing techniques and mindfulness meditation.
Set limits for yourself and others by learning to express emotions in ways that don't push people away or make you feel abandoned. Don't assume what other people are thinking or feeling about you.
Reach out to others with BPD to share experiences, build a support system of people who respect you, and keep up a healthy lifestyle with good food, physical activity, and social connection.
Perhaps most importantly: don't blame yourself for the condition, but do take responsibility for treating it.
What is the bottom line on borderline personality disorder?
Borderline personality disorder is intense, confusing, and often exhausting, but it is one of the most treatable conditions in mental health. Most people improve greatly, and many go on to build stabler relationships and more fulfilling lives. If you recognize these patterns in yourself or someone you love, the single most important step is connecting with a mental health professional, ideally one experienced with BPD.
Next steps: If you're in crisis, call or text 988 (U.S.) now. Otherwise, start with your primary care doctor or a mental health professional for a proper evaluation, and ask specifically about dialectical behavior therapy (DBT) and other evidence-based options.
FAQ
What is borderline personality disorder in simple terms?
Borderline personality disorder is a mental health condition that changes how you feel about yourself and others. It shows up as unstable, intense relationships, sudden mood swings, impulsiveness, an unhealthy self-image, and a strong fear of being left alone. It usually begins by early adulthood and makes everyday functioning harder, but it responds well to treatment.
How do you know if you have borderline personality disorder?
The signs form a pattern: a strong fear of abandonment, relationships that swing between idealizing someone and seeing them as cruel, quick shifts in your self-image and goals, mood swings lasting hours to days, impulsive or risky behavior, chronic emptiness, intense anger, and threats of suicide or self-injury, often triggered by fears of rejection. Only a doctor or mental health professional can make the diagnosis, usually through a detailed interview and mental health evaluation in adulthood.
Is borderline personality disorder curable?
There is no quick cure, but recovery is real. Most people with BPD improve greatly with treatment, especially structured talk therapies like dialectical behavior therapy. Mood swings, anger, and impulsiveness often get better with age. Some people continue to struggle with certain symptoms, but treatment makes daily functioning easier and life more fulfilling.
What is the best treatment for borderline personality disorder?
Psychotherapy (talk therapy) is the main treatment. Dialectical behavior therapy (DBT), built specifically for BPD, teaches skills for managing emotions, handling distress, and improving relationships. Cognitive behavioral therapy and other structured approaches also help. Medicines aren't approved specifically for BPD, but antidepressants, antipsychotics, and mood stabilizers can help with symptoms or related conditions like depression. Working with a professional experienced in BPD gives you the best chance of success.
Can borderline personality disorder be prevented?
The causes aren't fully known, so it can't be reliably prevented. However, knowing the risk factors, a family history of the condition and a stressful, abusive, or unstable childhood, can prompt earlier support. Getting professional help early, learning coping skills, avoiding drugs and alcohol, and building a support system can all reduce how severely the condition affects a life.
Disclaimer: This article is for general informational purposes only and does not constitute medical advice. Always consult a qualified health care provider for individual questions.
What causes borderline personality disorder?
There is no single cause. It likely comes from a mix of genes, differences in how the brain handles emotions and life experiences such as childhood trauma, abuse, neglect or unstable relationships.
What is dialectical behavior therapy (DBT)?
DBT is a type of talk therapy made for people with borderline personality disorder. It teaches skills for staying in the moment, handling distress, managing strong emotions and building healthier relationships.
Can medicine treat borderline personality disorder?
No medicine is approved by the FDA to treat borderline personality disorder itself. Medicines may help related problems such as depression, anxiety or mood swings, but therapy is the main treatment.
How is borderline personality disorder different from bipolar disorder?
Bipolar disorder causes distinct periods of mania or depression that last days to weeks. In borderline personality disorder, moods often shift within hours, usually in response to stress in relationships, and a mental health professional can tell the two apart.
How can I support a loved one with borderline personality disorder?
Learn about the condition, stay calm, listen and take their feelings seriously, and set clear and kind boundaries. Encourage treatment, and look after your own health, for example through family programs or support groups.
Related Reading
Assertive Community Treatment (ACT): What It Is and Benefits explains assertive community treatment.
References
Mayo Clinic Staff. Borderline personality disorder - Symptoms and causes. Mayo Clinic. January 31, 2024. https://www.mayoclinic.org/diseases-conditions/borderline-personality-disorder/symptoms-causes/syc-20370237
Mayo Clinic Staff. Borderline personality disorder - Diagnosis and treatment. Mayo Clinic. January 31, 2024. https://www.mayoclinic.org/diseases-conditions/borderline-personality-disorder/diagnosis-treatment/drc-20370242
988 Suicide & Crisis Lifeline. If you need to talk, the 988 Lifeline is here. 988 Lifeline. Accessed October 14, 2026. https://988lifeline.org/
Veterans Crisis Line. 24/7, confidential crisis support. Veterans Crisis Line. Accessed October 14, 2026. https://www.veteranscrisisline.net/
National Institute of Mental Health. Borderline Personality Disorder. National Institute of Mental Health (NIMH). Reviewed December 2024. https://www.nimh.nih.gov/health/topics/borderline-personality-disorder
National Alliance on Mental Illness. Borderline Personality Disorder. NAMI. Published April 2023. https://www.nami.org/types-of-conditions/borderline-personality-disorder/
Li Y, et al. Effect of dialectical behavior therapy on affective symptoms in borderline personality disorder: A systematic review and meta-analysis. Psychiatry Res. 2026;360:117055. PMID 41819776. https://doi.org/10.1016/j.psychres.2026.117055
Arqueros M, Soler J, Pascual JC. Stand-alone dialectical behavior therapy skills training for borderline personality disorder: A systematic review and meta-analysis. Personal Disord. 2026;17(6):460-473. PMID 42275028. https://doi.org/10.1037/per0000774
Cai M, et al. Efficacy of psychological interventions for adolescents with borderline personality disorder: a systematic review and meta-analysis. Front Psychiatry. 2026;17:1833555. PMID 42368806. https://doi.org/10.3389/fpsyt.2026.1833555
Comments