BACKGROUND: The concepts of mood and personality disorders have faced countless changes over the last decades. Historically, these concepts have been built in parallel, that is, mood and personality disorders have been considered as independent disorders with respect to diagnosis, prognosis and treatment. Recently, however, new proposes on the nosological conceptualization of these disorders have raised the question of a possible overlap between these nosological entities, making the differential diagnosis between these disorders difficult at times. OBJECTIVES: To carry out a literature review on the evolution of mood and personality disorders concepts under a historical perspective, focusing on diagnostic-related issues. METHOD: A comprehensive MEDLINE literature search (1990-2007) was conducted. RESULTS: Contrarily to the concept of mood disorder, which seems to be stable and relatively unchanged since its first description, the concept of personality disorder shows considerable variation over the different literature findings. Thus, both groups of disorders have been conceptualized not only in a categorical point of view but also according to a dimensional approach. The last one may be at least partially accountable for the difficulties sometimes observed in the differential diagnosis of these disorders. DISCUSSION: The differential diagnosis between mood and personality disorders may still represent a serious problem in clinical settings, and can not be completely clarified in light of available evidence. A better understanding of the pathophysiological basis of these disorders, as well as the more accurate identification of their biological markers can help redefining their concepts and their nosological current status.
Mood disorder; bipolar disorder; depressive disorder; personality disorder; history; differential diagnosis