Timo Säämänen, Juha Voutilainen, Jari Lahti, Erkki Isometsä, Martti Heikkinen and Marius Lahti
Background: Major depressive disorder and borderline personality disorder are highly comorbid. In previous studies, certain Five-Factor Model personality dimensions have been associated with both borderline personality disorder and major depression. Multiple Self States Model personality fragmentation has also been associated with borderline personality disorder. However, the specificity of these associations remains unclear. We examined whether personality fragmentation and Five-Factor Model personality dimensions are associated with borderline personality disorder symptoms among depressed psychiatric patients.
Methods: A sample of 43 depressed psychiatric hospital inpatients filled in the Personality Structure Questionnaire, the NEO Personality Inventory, and the Structured Clinical Interview for DSM-IV Axis II Personality Questionnaire on borderline personality disorder symptoms. We examined the associations of Five-Factor Model personality dimensions and Multiple Self States model personality fragmentation with borderline personality disorder symptom sum-score and with the number of endorsed Diagnostic and Statistical Manual of Mental Disorders borderline personality disorder symptoms with linear regression analyses. The analyses were adjusted for age and education level of the participants and/or concurrent depressive symptoms.
Results: Higher personality fragmentation and higher Neuroticism were associated with significantly higher borderline personality disorder symptom sum-score and with a significantly higher number of endorsed borderline personality disorder symptoms. These associations were independent of sociodemographic covariates and concurrent depressive symptoms.
Conclusions: Among depressed patients, higher levels of borderline personality disorder symptoms show independent, significant associations with higher personality fragmentation and higher Neuroticism. These two personality dimensions thus informatively characterize depressed patients with high levels of borderline personality disorder symptoms.