Social integration and social support have a substantial influence on individual health and longevity, an effect assumed to be mediated through reduced stress reactivity in support recipients. However, considerable variability in individual responses to social support has been documented, suggesting that the beneficial effect of social support interacts with early experiences, genetically influenced differences in biological systems mediating social behavior, personality traits, and psychopathology. Here we outline the historical background of social support research, including epidemiological studies, laboratory studies, and field studies on the subject of social support and health, with regard to different psychobiological effector systems. Most recent research has focused on brain mechanisms which link social integration or social support with reduced neural threat responses. As numerous mental disorders are associated with considerable social impairment, understanding the potentially underlying mechanisms of neural plasticity in relation to social support, stress buffering and health in these disorders can help tailor new diagnostic and treatment strategies. Thus, theories of socially-driven emotional learning and memory, as presented in this review, might eventually lead to psychobiology-based treatment concepts for mental disorders involving social deficits.
Keywords: Social support; autonomic nervous system (ANS); cortisol; hypothalamus pituitary adrenal (HPA) axis; oxytocin; psychobiology; safety signals; stress.