The Functional Domain of Self-Other Regulation

Depression and personality disorder, in particular borderline personality disorder as defined by DSM and ICD classifications, are characterized by great phenomenological heterogeneity, and high comorbidity with each other and with other psychiatric disorders. These characteristics suggest that several domains of mental functioning are differentially affected, to give rise to one or another diagnosis and their comorbidities. This chapter reviews and links the evidence related to the impairments in functioning of the self-other domain, particularly in adult depression, through advancing a model based on three of its main component systems: stress regulation (negative valence and arousal/regulatory systems), reward (positive valence systems), and mentalizing (system for social processes or social cognition) systems, which we see as interconnected. For each of these systems, we review and link the evidence arising from genetic, neurophysiological and behavioral domains. The chapter follows a developmental psychopathology perspective, which highlights the developmental cascades that give rise to such psychopathology. Finally, we propose an understanding of comorbidity and heterogeneity, future lines for research and for the development of evidence-based interventions.