We describe the 9 diagnostic criteria in ways that reflect lived experience, research findings, and the emotional processes beneath them. These features are interconnected and understood as patterns that develop over time, rather than as isolated behaviors or emotional reactions.

1. Intense Fear of Abandonment

A strong sensitivity to real or perceived rejection, distance, or loss of connection. This may lead to heightened emotional responses or urgent efforts to maintain closeness, especially during moments of stress or uncertainty.

2. Unstable or Rapidly Changing Relationships

Relationships may feel intense, emotionally charged, or unpredictable. Shifts in closeness often reflect emotional vulnerability and sensitivity to perceived changes in others’ availability or responsiveness.

3. Unstable Sense of Self or Identity

Difficulty maintaining a consistent sense of self, values, or goals. This may include self-doubt, fluctuating self-esteem, or uncertainty about one’s identity or direction in life.

4. Impulsive or Self-Damaging Behaviors

Impulsive actions—such as risky behaviors, substance use, or spending—often occur in response to overwhelming emotions. These behaviors are typically attempts to manage distress rather than intentional self-harm.

5. Suicidal Thoughts or Self-Harm Behaviors

Recurrent thoughts of suicide, self-harm, or related behaviors may emerge during periods of intense emotional pain. These are best understood as signals of distress and efforts to cope, not attention-seeking.

6. Intense and Rapidly Shifting Emotions

Emotions may escalate quickly, feel extremely painful, and take longer to settle. Mood shifts are often reactive to environmental or interpersonal triggers rather than occurring in discrete episodes.

7. Chronic Feelings of Emptiness or Low Self-Worth

Many individuals experience persistent feelings of inner emptiness, worthlessness, or emotional numbness. Others describe this more as low self-esteem, harsh self-judgment, or a lack of inner stability.

8. Difficulty with Anger or Intense Emotional Expression

Strong emotional reactions—sometimes expressed as anger—can occur when emotions feel overwhelming. Research and clinical experience show that shame is often more central and more common than anger, even when anger is more visible.

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A Note on Anger and Shame

Problems with anger are included in the DSM description of BPD, and anger can certainly be present. However, research and clinical experience suggest that shame is often far more common and more central than anger for many individuals with BPD.

Anger is more visible and therefore more likely to be emphasized, while shame is frequently internalized and overlooked. Understanding this distinction is important for reducing stigma and for providing care that addresses the emotions people with BPD experience most intensely.

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9. Stress-Related Changes in Thinking or Perception

During periods of high stress or emotional overload, individuals may experience transient paranoia, dissociation, or difficulty thinking clearly. These experiences are typically short-lived and closely tied to emotional intensity.

Clinicians use standardized diagnostic guides—the DSM and ICD—to make diagnoses.  These guides list diagnostic criteria—put more simply, possible signs of BPD—and identify what’s required to make a formal diagnosis. Under the DSM a diagnosis requires any five of the nine signs. A clinical assessment may involve:

• A detailed clinical interview exploring current concerns, emotional experiences, relationships, and developmental history
• Review of symptom history and duration to determine whether difficulties have been present over time and across situations
• Evaluation of emotional, relational, and behavioral patterns, rather than individual behaviors in isolation
• Consideration of alternative or co-occurring diagnoses, given the overlap between many mental health conditions

Clinicians assess whether these patterns are:

• Persistent over time
• Pervasive across contexts
• Associated with meaningful impairment in functioning

Understanding how diagnosis is made helps shift the focus away from labels and toward the underlying patterns that matter most. Regardless of how diagnostic language evolves, the challenges associated with chronic emotion dysregulation and relational instability remain real and require effective, compassionate care.

The DSM has described borderline personality disorder (BPD) for more than four decades. While the way BPD is classified and discussed has evolved, the core understanding of the condition has remained largely consistent.

DSM-III (1980): First formal definition. BPD was officially introduced as a diagnosis in DSM-III. This marked the first time it was clearly defined using specific criteria rather than vague or theoretical descriptions.

At this stage, BPD was described as a pattern of:

• Intense and unstable relationships
• Strong and rapidly changing emotions
• Impulsive behaviors
• Unstable sense of self
• Stress-related symptoms such as paranoia or dissociation

This edition established BPD as a distinct condition rather than something “in between” other diagnoses.

DSM-IV (1994): Clarifying without major changes. In DSM-IV, the basic description of BPD stayed the same. The manual continued to list nine characteristics, with a diagnosis made when any five were present.

The language was refined and clarified, and the overall understanding of BPD did not change. The emphasis remained on long-standing patterns of emotional, relational, and behavioral instability.

DSM-5 (2013) and DSM-5-TR (2022): Same criteria, new context. In DSM-5, the formal criteria for BPD stayed exactly the same as in DSM-IV. What changed was the broader context:

• Personality disorders were no longer placed in a separate category from other mental health conditions
• The DSM introduced an alternative model that looks at personality functioning and traits, though this model is optional and not used for most diagnoses

Despite ongoing discussion about new ways to describe personality disorders, the original BPD criteria remain the primary diagnostic standard.

DSM-6 (Future): Ongoing discussion. Researchers and clinicians continue to explore more dimensional and less stigmatizing ways to describe personality and emotional difficulties, and any future updates, including a potential name change for borderline personality disorder, remain in development.

Across all DSM editions, BPD has consistently been understood as involving:

• Chronic difficulty regulating emotions
• Instability in relationships and self-image
• Patterns that develop over time, not isolated behaviors

While diagnostic language and structure may change, the lived experience and underlying challenges associated with BPD have remained clearly recognized.

BPD and complex PTSD can appear similar, especially when emotional dysregulation, relationship difficulties, and identity disruption are present. This has led some to assume that BPD is simply a trauma-based condition.

A key distinction is that complex PTSD requires significant trauma exposure, while BPD does not. Although many people with BPD have trauma histories, trauma alone does not determine the diagnosis. In some cases, the overall pattern of chronic emotion dysregulation fits BPD more closely than complex PTSD.

Clinical takeaway: When severe, ongoing emotion dysregulation is central, treatment should directly address emotion regulation—regardless of which diagnostic label is used.

Depression is often the diagnosis people receive when hopelessness, withdrawal, or low functioning are most visible. Some individuals with depression also meet criteria for BPD, particularly when emotion dysregulation has been present for many years and multiple treatment attempts have been unsuccessful.

Clinical takeaway: When standard treatments for depression repeatedly fail, it may be helpful to consider whether chronic emotion dysregulation—and possibly BPD—is part of the picture.

There can be overlap between BPD and other personality disorders, and in some cases a person may meet criteria for more than one diagnosis. More often, however, individuals meet criteria for one primary condition.

Antisocial Personality Disorder

When comparing BPD and antisocial personality disorder, overlap in diagnostic criteria is relatively limited. One practical distinction involves context and consistency:

• Many people do things they later regret when they are emotionally dysregulated.
• If problematic behaviors (such as aggression or impulsivity) occur only during periods of emotional dysregulation, this is different from the more pervasive, stable pattern expected in antisocial personality disorder.

Behaviors that fluctuate with emotional state are often more consistent with BPD than with antisocial personality disorder, even if some criteria appear to overlap.

NPD, HPD, and Why “Cluster B” Can Be Misleading

In older diagnostic frameworks, personality disorders were grouped into clusters (Cluster A, B, and C). Cluster B includes four diagnoses: borderline, antisocial, narcissistic, and histrionic personality disorder. The term “Cluster B” is commonly used in everyday language, including by people with lived experience. The challenge is that, in practice, some of these diagnoses—particularly narcissistic and histrionic personality disorder—have low diagnostic reliability, meaning clinicians often disagree about who meets criteria. BPD and antisocial personality disorder are the two Cluster B diagnoses for which diagnostic reliability is generally stronger.

Clinical takeaway: Patterns involving emotion dysregulation, impulsivity, self-harm, unstable relationships, and identity disturbance are more consistent with BPD than with common popular uses of other personality disorder labels.