Borderline Personality Disorder: Signs in Adults and Why Talk Therapy Comes First

Borderline personality disorder (BPD) can make feelings arrive faster and hit harder than the situation seems to call for, and it can make relationships feel like they are always on the edge. The National Institute of Mental Health (NIMH) calls it a serious mental illness that affects how a person feels about themselves and others. It also says evidence-based treatments have been shown to help many people.

Signs NIMH describes

• Efforts to avoid being abandoned, real or imagined, such as rushing into or out of relationships
• Close relationships that are intense and unstable
• Strong sensitivity to rejection, and feeling alienated or alone
• A shifting, unsteady sense of who you are
• Intense moods that change quickly, with episodes lasting from a few hours to a few days
• A lasting sense of emptiness
• Intense anger, or trouble keeping anger in check
• Dissociation, such as feeling cut off from yourself or your surroundings
• Self-harm, or recurring thoughts of suicide

NIMH adds that people with BPD tend to see things in extremes, all good or all bad. Not everyone has every symptom, and severity and duration vary from person to person.

BPD and bipolar disorder are not the same

Both involve big mood changes, so the two get confused. NIMH explains that BPD symptoms happen without the significantly elevated mood seen in manic or hypomanic episodes, which is a key feature of bipolar disorder. BPD often occurs alongside other conditions, including depression, bipolar disorder and ADHD, so a careful history matters. Read how clinicians tell mood swings from bipolar disorder.

How it is diagnosed

Borderline personality disorder is a DSM-5-TR diagnosis made by a qualified clinician. NIMH says it is usually diagnosed in late adolescence or early adulthood. Our practice sees adults 18 and older.

Why talk therapy comes first

NIMH says psychotherapy is the primary treatment. It names dialectical behavior therapy (DBT), which was developed specifically for people with BPD and teaches skills to manage intense emotions, reduce self-destructive behavior and improve relationships. It also names cognitive behavioral therapy (CBT), which helps people identify and change beliefs and behaviors that grow out of inaccurate views of themselves and others.

NIMH says medication is not a first-line treatment for the disorder itself, though it may be added for specific symptoms or for a condition that occurs alongside it. Any medication when indicated is decided jointly with the patient.

Our counselors draw on CBT, acceptance and commitment therapy, trauma-informed care and DBT-informed approaches. We do not offer family therapy, so your provider can coordinate a referral for it, or for a dedicated DBT program, when either looks like a better fit.

If you love someone with BPD

NIMH suggests learning about the disorder, offering patience and encouragement, getting to know the treatment plan, encouraging your loved one to ask about family therapy, and finding a counselor of your own, separate from theirs. Take any mention of self-harm or suicide seriously. NIMH also says change can be hard and frightening for people with BPD, but things can improve with time.

Care at Hope Behavioral Medicine

We offer evaluation, counseling and follow-up for borderline personality disorder in West Ashley and by secure video anywhere in South Carolina. Request an appointment.

Sources: NIMH, Borderline Personality Disorder (revised 2025); American Psychiatric Association, DSM-5-TR (borderline personality disorder).

This article is general information, not medical advice, and does not create a patient–provider relationship. Every situation is different, so see a provider who can evaluate yours and develop a plan of care. Any medication discussed here may not be right for you: the right choice depends on your diagnoses, other health conditions and current medicines, so take medication only as directed by the provider managing your care. If you are ever in doubt about an emergency, call 911 or go to the nearest emergency room.