How can you diagnose a personality disorder?

Diagnosing Personality Disorders

Personality disorders should be diagnosed using a dimensional approach that assesses problems in functioning of aspects of the self (e.g., identity) and/or interpersonal dysfunction (e.g., managing conflict in relationships), rather than relying solely on categorical classifications. 1

Core Diagnostic Framework

The ICD-11 has moved away from the traditional categorical approach to personality disorders, adopting a more evidence-based dimensional model:

Primary Assessment Components

1. Single Personality Disorder Diagnosis:

   • Assess for problems in functioning of aspects of self (identity issues)
   • Evaluate interpersonal dysfunction (difficulty managing relationships)
   • Determine severity level (mild, moderate, or severe) 1

2. Optional Trait Qualifiers:

   • Negative affectivity
   • Detachment
   • Dissociality
   • Disinhibition
   • Anankastia
   • Borderline pattern 1

Diagnostic Process

1. Structured Clinical Interviews:

   • Use validated diagnostic interviews such as:
     • Structured Clinical Interview for DSM-5 (SCID-5) for adults
     • Mini International Neuropsychiatric Interview (MINI version 7.0)
     • Structured Clinical Interview for Obsessive-Compulsive Spectrum Disorders (SCID-OCSD) 2

2. Multi-method Assessment Approach:

   • First administer a self-report inventory to identify maladaptive personality functioning
   • Follow with a semi-structured interview to verify the personality disorder's presence 3

3. Severity Assessment:

   • Determine if symptoms are time-consuming
   • Evaluate level of distress or functional impairment
   • Assess insight into the unreasonableness of behaviors 2

Key Diagnostic Considerations

Dimensional vs. Categorical Approach

The shift from categorical to dimensional classification in ICD-11 addresses several limitations of previous approaches:

• Multiple personality disorder diagnoses often overlapped in the same patient
• Categorical approaches lacked empirical support
• Dimensional approach better reflects clinical reality 1

Common Pitfalls to Avoid

1. Overlooking Personality Disorders:

   • PDs are common in all medical settings but frequently go undetected 4
   • Patients rarely seek help specifically for personality disorders but for other medical issues 5

2. Misattribution of Relationship Problems:

   • Patients with personality disorders often attribute interpersonal problems to others 4
   • This can complicate the diagnostic process

3. Comorbidity Challenges:

   • Comorbidity with other mental disorders is common (present in 90% of cases)
   • Personality disorders can negatively affect course and treatment outcomes of other conditions 2, 4

4. Cultural Variations:

   • While specific content of symptoms may vary across cultures, core dysfunction patterns remain consistent 2

Impact on Health and Treatment

• Personality disorders are associated with premature mortality and suicide 4
• Patients with personality disorders, particularly borderline and schizotypal, utilize extensive mental health resources 6
• PDs affect both clinical presentation and outcomes of other medical problems 5

Practical Approach to Assessment

1. Initial Screening:

   • Look for persistent patterns of interpersonal difficulties
   • Assess for problems with emotional regulation
   • Evaluate self-concept and identity issues

2. Comprehensive Assessment:

   • Document temporal stability of traits (persistent over time)
   • Establish empirical basis for diagnostic thresholds
   • Consider impact of other disorders on assessment 3

3. Management Recommendations:

   • Tolerate the patient's affect (anger, anxiety) while being firm and kind
   • Accept dependency and vulnerability
   • Respect the underlying coping style
   • Identify and treat any underlying symptom disorders
   • Document patient interactions objectively 7

By following this structured approach to diagnosis, clinicians can better identify personality disorders and provide appropriate treatment planning, ultimately improving patient outcomes in terms of morbidity, mortality, and quality of life.