The overlap between personality disorders and major depressive disorder (MDD)

Background. Research studies have focused attention on the importance of the comorbidity of personality disorders and depression. Methods. The present review examines seven potential explanations for the overlap to clarify the nature of the relationship, if any, between depression and personality disorder diagnoses. Results. There may be many explanations for the potential overlap of personality disorders (PD) and major depressive disorder (MDD). For example, the distinction between states and traits may not be as clear and definitive as suggested in the DSM-IV. In some cases, depression may influence personality pathology, and may even lead to personality disorders. In other cases, personality disorders may lead to MDD. Conclusion. Further research may clarify the nature of the relationship, if any, between depression and personality disorder diagnoses, as well as the relationship between comorbidity and treatment response.