Determining essential dimensions for the clinical approximation of personality disorder severity: multi-method study

Area of Science:

• Psychiatry and Psychology
• Clinical Psychology
• Personality Disorders

Background:

• The ICD-11 now uses dimensional assessment of personality disorder severity (PDS) instead of categorical diagnoses.
• This shift emphasizes impairments in self- and interpersonal functioning.
• Clinicians and researchers need to adapt to these new diagnostic approaches.

Purpose of the Study:

• To identify which PDS dimensions, across different assessment methods, best predict overall PDS.
• To compare the predictive value of various conceptualizations of personality functioning.

Main Methods:

• Utilized semi-structured interviews and self-reports in clinical samples (n=534) from Switzerland and Germany.
• Calculated a latent general factor for PDS (g-PDS) using a correlated trait correlated (method - 1) model (CTC(M-1)).

Main Results:

• Four interview-assessed PDS dimensions (defense mechanisms, desire/capacity for closeness, sense of self, comprehension of others) explained 91.1% of g-PDS variance.
• Two of these dimensions alone explained 81.8-91.3% of the variance.
• Self-report dimensions predicted 61.3% of a latent interview-based score, with all self-reported dimensions explaining 65.2% of variance.

Conclusions:

• Specific PDS dimensions, particularly those related to intimacy and identity, are strong predictors of overall PDS.
• Focusing on these key dimensions may offer an efficient method for PDS assessment in time-limited clinical settings.