You or someone you care about may have received multiple mental health diagnoses over time across different providers, settings, or stages of life. These may include:

• Borderline personality disorder (BPD)
• Emotionally unstable personality disorder (EUPD)
• Post-traumatic stress disorder (PTSD)
• Complex PTSD
• Depression
• Anxiety disorders
• Substance use disorders
• Eating disorders
• These conditions frequently co-occur with difficulties in emotion regulation.

Receiving multiple diagnoses can feel disorienting and may raise questions: Which one is accurate? Do they conflict? Why do clinicians differ?

The presence of multiple diagnoses does not indicate separate or unrelated problems, rather reflects overlapping patterns that are often connected and reinforce one another.

These conditions are often best understood as interrelated, rather than separate or isolated.

Across these diagnoses, the most consistent common link is severe and chronic emotion dysregulation.

This shared pattern helps explain why multiple diagnoses often appear together, and why symptoms can look different from person to person while still reflecting similar underlying difficulties. Severe and chronic emotion dysregulation includes a range of emotional and behavioral challenges that are across diagnostic categories.

By focusing on common links rather than isolated labels, it becomes easier to:

• see the whole picture
• understand why distress clusters the way it does
• choose treatment strategies that match the underlying issue

In real-world clinical settings—particularly in public and community mental health—diagnostic labels often matter less than the presenting problems. Core concerns frequently include suicidality, self-harm, and chronic emotion dysregulation, regardless of the specific diagnosis assigned.

Clinical care focuses on addressing patterns of distress and risk, not on treating a diagnostic label. Effective treatment targets the underlying emotional and relational difficulties that drive suffering, rather than the name used to describe them.

The DSM is a diagnostic manual published by the American Psychiatric Association. It provides standardized criteria for diagnosing mental health conditions.

Mental health professionals use the DSM to:

• Describe patterns of symptoms
• Support accurate and consistent diagnoses
• Guide treatment planning
• Facilitate communication among professionals

The DSM is primarily used in the United States and focuses specifically on mental health conditions.

The ICD is a global diagnostic classification system developed and maintained by the World Health Organization (WHO). It includes codes for both medical and mental health conditions.

Healthcare professionals use the ICD to:

• Classify diseases and health conditions
• Track health statistics worldwide
• Support diagnosis, billing, and research
• Maintain consistency across countries and healthcare systems

The ICD is used internationally and is the required diagnostic system for reporting health conditions in many countries.

The DSM and ICD provide a shared language for describing health conditions. They help ensure consistency in diagnosis, research, and communication, but they do not define a person’s identity or fully capture an individual’s lived experience.

Diagnoses are best understood as clinical tools—not labels that describe the whole person.

The term borderline personality disorder (BPD) originates from the DSM. In contrast, the ICD has historically used the term Emotionally Unstable Personality Disorder (EUPD), including a borderline type, to describe a similar pattern of difficulties.

Although the terminology differs, these labels describe largely the same underlying challenges, particularly chronic emotion dysregulation and difficulties in relationships. The differences between DSM and ICD language are primarily differences in structure and emphasis, not in the core experiences being described.

DSM and ICD criteria are not direct equivalents. Most individuals who meet diagnostic criteria in one system would also meet criteria in the other, but there is not complete overlap. This lack of one-to-one correspondence highlights the inherent limitations and imperfections of diagnostic systems and underscores the importance of clinical judgment.

Diagnostic systems are not static. Both the DSM and ICD continue to evolve as research and clinical understanding grow. While future revisions are anticipated, changes in diagnostic language reflect efforts to improve accuracy, clarity, and clinical usefulness, not to deny or minimize lived experience.

These systems are not perfectly aligned and are shaped by different scientific, cultural, and international considerations. Understanding this context helps place diagnosis where it belongs: as a tool to support care, communication, and treatment planning—not as a definitive explanation of a person’s experience.

The DSM outlines nine diagnostic criteria for borderline personality disorder, and a diagnosis is made when at least five are present. 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.

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.

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

To meet DSM criteria, an individual must meet any five of nine characteristics, which allows for many possible combinations. Because of this, BPD can present differently from person to person. In clinical practice, however, certain patterns appear more consistently—particularly chronic emotion dysregulation and difficulties in relationships—while other features vary more widely.

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 – There is no published DSM-6 yet, and no finalized changes to how BPD will be diagnosed. Researchers and clinicians continue to explore more dimensional and less stigmatizing ways to describe personality and emotional difficulties, and any future updates including a name change remain under 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.

The DSM provides diagnostic criteria to support consistency and communication in mental health care. It does not explain the cause of BPD or define an individual’s identity.

A diagnosis of BPD is best understood as a clinical framework that helps guide treatment and support—not as a judgment about character or worth.

Under the ICD-11, a personality disorder is defined as a persistent disturbance in:

• How a person experiences and understands themselves
• How they relate to others
• How they regulate emotions and behavior

These patterns are long-standing, inflexible, and associated with significant distress or impairment in functioning.

Rather than diagnosing specific personality disorder categories, the ICD-11 focuses on severity and core personality functioning.

In ICD-11, clinicians may add a “borderline pattern” specifier when an individual’s presentation includes features traditionally associated with borderline personality disorder.

This pattern is characterized by difficulties such as:

• Marked emotional instability
• Intense and unstable relationships
• Fear of abandonment
• Unstable self-image
• Impulsivity
• Self-harm or suicidal behaviors
• Chronic feelings of emptiness

The specifier is used to describe the style and pattern of emotional and relational functioning, rather than to assign a fixed category.

Diagnosis under the ICD-11 involves:

• Determining whether a personality disorder is present
• Assessing the severity (mild, moderate, or severe)
• Identifying prominent trait domains
• Adding a borderline pattern specifier when appropriate

This approach emphasizes how functioning is affected, rather than counting a specific number of symptoms.

ICD-10 (Introduced 1992; In Effect 1993)

With the publication of ICD-10 in 1992 (and implementation beginning in 1993), the World Health Organization introduced the term “Emotionally Unstable Personality Disorder, borderline type.” This marked the point at which borderline personality disorder was formally classified under the broader category of emotionally unstable personality disorder, with “borderline type” specified as a distinct presentation. In this system, BPD is recognized as a specific diagnostic category.

ICD-11 (Published 2019; In Effect 2022)

In ICD-11, published in 2019 and officially in effect as of January 1, 2022, the term borderline personality disorder is no longer used as a standalone diagnosis. Instead, ICD-11 uses a dimensional model of personality disorder. Clinicians diagnose a personality disorder based on severity and may add a “borderline pattern” specifier to describe features traditionally associated with BPD.

The ICD-11 framework:

• Focuses on emotional and interpersonal functioning
• Uses a dimensional severity-based model
• Allows for more individualized descriptions
• Aims to reduce stigma associated with categorical labels

The borderline pattern specifier helps clinicians communicate important clinical features while recognizing that personality presentations exist on a spectrum.

Like the DSM, the ICD provides a clinical framework to support diagnosis, treatment planning, and communication. It does not define a person’s identity or explain the full complexity of their lived experience.

The ICD-11 approach emphasizes understanding patterns of emotional and relational functioning rather than assigning rigid labels.

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 emotional 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.

Bipolar disorder, particularly Bipolar I, is a distinct condition but is often confused with BPD. Both can involve mood changes, but the patterns differ. Bipolar disorder involves discrete mood episodes. BPD involves rapid, trigger-linked emotional reactivity, especially in relationships.

Clinical takeaway: Accurate differentiation matters because treatment approaches differ significantly.

Mental health diagnoses are descriptive frameworks, not perfect categories. Many conditions share overlapping features, and diagnostic systems continue to evolve. This overlap can create confusion and contribute to the mistaken belief that certain diagnoses are interchangeable.

Understanding BPD as a distinct condition—while acknowledging overlap—supports more accurate assessment, better-matched treatment, and improved outcomes. Clarifying these distinctions is not about labeling; it is about ensuring people receive care that truly fits their needs.

About Personality Disorder Categories

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.

In practice, some of these diagnoses—particularly narcissistic and histrionic personality disorder—have low diagnostic reliability, meaning clinicians often disagree about who meets criteria. There is also limited high-quality research supporting specific, evidence-based treatments for those conditions. For this reason, many clinicians place less emphasis on those labels.

Borderline personality disorder (BPD) and antisocial personality disorder are the two Cluster B diagnoses for which diagnostic reliability is generally stronger.

Overlap Does Happen—And It’s Often Limited

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.

When comparing BPD and antisocial personality disorder specifically, 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.

Why “Cluster B” Can Be Misleading

The term “Cluster B” is commonly used in everyday language, including by people with lived experience. The challenge is that only a small number of personality disorder diagnoses can be made reliably across clinicians, and few have well-established, evidence-based treatments.

BPD is one of the diagnoses where clinicians can achieve better agreement when criteria are clearly defined and severity thresholds are specified. Many other labels are less reliable and are also heavily shaped by popular culture, which adds to confusion and stigma.

A Practical Clinical Perspective

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.

Diagnosis should focus on patterns over time, not isolated behaviors or moments of crisis.