How Borderline Personality Disorder Affects Emotions and Behavior

Emotional Pain Like a Third-Degree Burn

Marsha Linehan — the psychologist who developed Dialectical Behavior Therapy (DBT) and who later disclosed her own BPD diagnosis — described the emotional experience of borderline personality disorder as analogous to having third-degree burns over 90% of the body: ordinary touch that barely registers for others is excruciating. The National Institute of Mental Health estimates BPD affects 1.6% of U.S. adults in any given year, rising to 5.9% in community samples using structured interviews. It accounts for 20% of psychiatric inpatient admissions and is associated with among the highest rates of self-harm and suicide attempts of any psychiatric diagnosis — with approximately 10% of BPD patients eventually dying by suicide, a rate 50 times higher than the general population. BPD is frequently misdiagnosed as bipolar disorder, depression, or PTSD, delaying appropriate treatment by an average of 10 years.

DSM-5 Diagnostic Criteria

BPD diagnosis requires five or more of nine criteria, representing a persistent pattern beginning in early adulthood across multiple contexts:

• Frantic efforts to avoid real or imagined abandonment
• A pattern of unstable and intense interpersonal relationships alternating between extremes of idealization and devaluation ("splitting")
• Identity disturbance: markedly and persistently unstable self-image or sense of self
• Impulsivity in at least two potentially self-damaging areas (spending, sex, substance use, reckless driving, binge eating)
• Recurrent suicidal behavior, gestures, or threats, or self-mutilating behavior
• Affective instability due to marked mood reactivity (episodic dysphoria, irritability, or anxiety lasting hours to rarely more than a few days)
• Chronic feelings of emptiness
• Inappropriate, intense anger or difficulty controlling anger
• Transient, stress-related paranoid ideation or severe dissociative symptoms

The Core Features: Emotional Dysregulation

Linehan's biosocial theory proposes that BPD develops from the interaction of biological emotional sensitivity with an invalidating environment during development. Individuals with BPD are born with a biologically more reactive limbic system — faster emotional arousal, higher intensity responses, and slower return to emotional baseline — and develop in environments where their emotional experiences are routinely dismissed, punished, or contradicted.

The result is a person who never learns to accurately label, tolerate, or regulate emotions, and who lacks effective interpersonal skills because vulnerability was never validated. This creates extreme behavioral responses to emotional pain — including self-harm (which many patients describe as providing temporary relief from overwhelming emotional states) and suicidal behavior as crisis communication.

Neurobiological Findings

Splitting and Interpersonal Patterns

Splitting — seeing people and situations as entirely good or entirely bad, with rapid shifts between these poles — is the most characteristic interpersonal feature of BPD. It reflects difficulty integrating contradictory feelings about the same person (object constancy). A person who is deeply admired and idealized one day becomes the target of intense devaluation and rage the next, triggered by perceived abandonment or disappointment. This creates chaotic, intense relationships characterized by repeated ruptures and reconciliations.

Fear of abandonment drives much of this interpersonal intensity. Actual separation or even perceived slights are experienced as catastrophic rejections. Frantic efforts to avoid abandonment — including repeated calls, threats of self-harm, or clinging behaviors — often produce the very abandonment they are intended to prevent, reinforcing the BPD patient's core belief that they are fundamentally unlovable or defective.

Self-Harm and Suicidality

Self-harm in BPD (cutting, burning, hitting) is most often not suicidal in intent but serves emotion-regulation functions: it provides sensory distraction from overwhelming emotional pain, triggers endorphin release, creates a visible external marker of internal suffering, or paradoxically restores a sense of control. Research suggests that approximately 69–80% of BPD patients engage in self-harm at some point.

Suicidal behavior must be taken seriously despite the diagnostic context. Approximately 60–70% of BPD patients make at least one suicide attempt, with an average of 3.4 attempts per patient across a lifetime. Lethality of attempts increases with age, depression comorbidity, and substance use disorders.

Treatment: Dialectical Behavior Therapy

DBT, developed by Marsha Linehan at the University of Washington, is the most evidence-based treatment for BPD. It teaches four skill sets:

• Mindfulness: non-judgmental observation of present-moment experience; the foundation skill that reduces emotional reactivity
• Distress tolerance: crisis survival strategies that help endure acute distress without self-harm (TIP skills, self-soothe, pros-and-cons)
• Emotional regulation: skills to identify, understand, modulate, and change emotional responses over time
• Interpersonal effectiveness: skills to maintain relationships, set limits, and maintain self-respect while getting needs met

Standard DBT combines weekly individual therapy, group skills training, telephone coaching, and therapist consultation. Multiple RCTs show DBT reduces self-harm, suicide attempts, psychiatric hospitalizations, and dropout from treatment compared with treatment-as-usual. Long-term outcomes are encouraging: the CLPS study found that 50% of BPD patients achieve stable remission by age 40.

This article is for informational purposes only. Consult a qualified healthcare professional for medical advice.