Disjunction in the subjective and objective measurement of co-occurring depression in borderline personality disorder – Implications for diagnosis

Objective: Research and clinical experience suggest that people with borderline personality disorder (BPD) are more likely to report greater severity of depressive symptoms than is objectively measured by their clinician. The prominence of low mood in association with BPD can result in the treatment of depressive symptoms being prioritised over the diagnosis and treatment of BPD. Method: This study investigated the utility of validated clinician-administered and self-report depression rating scales during psychiatric assessment of 49 clients diagnosed with BPD. Results: Considerable discrepancies emerged between client and clinician ratings of depression, with client-rated scales generating significantly higher depression scores. Both client-rated and clinician-rated depression scores were positively influenced by the severity of BPD symptoms. Conclusions: These findings raise questions about the interpretation of rating scales in clinical decision-making and highlight inherent uncertainty when diagnosing major depressive disorder in people who have borderline personality disorder. The accurate diagnosis of low mood has significant implications for the treatment and management of both disorders.