Comorbidity of personality disorders in mood disorders: A meta-analytic review of 122 studies from 1988 to 2010

Background: A meta-analysis was conducted to identify the proportions of comorbid personality disorders (PD) in mood disorders. Methods: We found 122 empirical papers published in the period 1980-2010 on participants having mood disorders in addition to a comorbid PD. Mood disorders were classified as bipolar disorders (BD), major depressive disorders (MDD) and dysthymic disorders (DYS). Several moderators were coded as well. Results: The risk of having at least one comorbid PD (any PD) was high across all three mood disorders (BD=.42, MDD=.45), but highest in DYS (.60). Cluster B and C PDs were most frequent in BD, while cluster C PDs dominated in MDD and DYS. Among the specific PDs, the paranoid (.11 versus .07/.05), borderline (.16 versus .14/13), histrionic (.10 versus .06/06) and obsessive compulsive (.18 versus .09/.02) PDs occurred more frequently in BD versus MDD/DYS, whereas the avoidant PD (.22 versus .12/.16) was most frequent in DYS versus BD/MDD. Moderator analyses showed higher comorbidity when diagnoses were based on questionnaires versus clinical interviews, DSM-III-R versus DSM-IV, more women were included or the duration of the disorder was longer. Age of onset yielded mixed results. Limitations: Blind rating of diagnoses was recorded, but was employed in too few studies to be usable as an indication of diagnostic validity. Conclusions: Personality disorders are common in mood disorders. Implications of the identified moderators as well as the new DSM-5 diagnostic system are considered. (C) 2013 Elsevier B.V. All rights reserved.