Diagnostic Process for Borderline Personality Disorder
Borderline personality disorder (BPD) requires a comprehensive psychiatric assessment using DSM-5 criteria, which must identify a pervasive pattern of instability in interpersonal relationships, self-image, affects, and marked impulsivity beginning by early adulthood. 1
Core Diagnostic Requirements
The diagnosis mandates gathering information from multiple sources using developmentally sensitive techniques, as patients often have impaired insight into their condition—more so than in primary psychiatric disorders. 1, 2 Confirmation from multiple informants is necessary because patients may not accurately report their symptoms due to fear, embarrassment, or concern about stigma. 1
Structured Assessment Approach
Clinical Interview Components
The diagnostic interview should systematically assess the following timeline elements: 1
- Age at onset and predominant early symptoms 1
- Relationship of symptoms to life events 1
- Progression of symptoms over time 1
Key Diagnostic Features to Evaluate
You must specifically assess these five core domains: 1
- Emotional dysregulation: Rapid mood shifts that are disproportionate to circumstances 1
- Interpersonal difficulties: Unstable relationships alternating between idealization and devaluation 1
- Identity disturbance: Varying self-concept oscillating between grandiosity and worthlessness 1
- Impulsivity: Pleasurable but self-damaging behaviors (spending, sex, substance use, reckless driving, binge eating) 1
- Self-harm behaviors: Recurring suicidal behavior, gestures, threats, or non-lethal self-injury 1
Mental State Examination Priorities
Special attention must be paid to suicidality during the mental state examination, as BPD carries high risk for suicide attempts. 1 The disorder is associated with considerable social and vocational impairments. 3
Structured Diagnostic Instruments
For formal assessment, use: 4
- Revised Diagnostic Interview for Borderlines 4
- Structured Clinical Interview for the DSM-5 Alternative Model for Personality Disorders 4
The McLean Screening Instrument for BPD (MSI-BPD) is the most commonly studied self-report scale, though the currently recommended cutoff of 7 may be too high for screening purposes and a lower threshold may be more appropriate. 5
Assessment of Comorbidities
You must screen for common co-occurring disorders, as most patients with BPD have additional psychiatric conditions: 1
- Depression (83% comorbidity) 3
- Anxiety disorders (85% comorbidity) 3
- Substance use disorders (78% comorbidity) 3
- Obsessive-compulsive disorder 1
- Social anxiety disorder 1
Obesity and binge-eating disorders are also common comorbidities. 4
Critical Diagnostic Pitfalls to Avoid
Clinicians frequently dismiss borderline personality traits as normal developmental concerns in adolescents, leading to underdiagnosis. 1 The disorder may be present in up to 6.4% of adult primary care visits—fourfold higher than in the general population—yet remains underdiagnosed. 4
Watch for behavioral clues during the assessment itself: 1
- Intense emotional reactions during the interview
- Splitting (viewing clinician as all-good or all-bad)
- Testing boundaries
- Excessive familiarity or hostility
Never challenge the patient's beliefs or provide excessive reassurance, as this may be interpreted as dismissive or fuel maladaptive patterns. Avoid excessive familiarity, schedule regular visits, set appropriate limits, and maintain awareness of your own emotional reactions. 4
Etiological Context
The development of BPD involves complex interaction of genetic predisposition and environmental factors, particularly adverse childhood experiences including physical/sexual abuse, and family psychopathology (history of suicidal behavior, bipolar illness, or substance abuse). 2 This context informs the diagnostic formulation but does not replace systematic assessment of current symptoms.