Aggressive behavior: Implications of dominance and subordination for the study of mental disorders

Individuals of gregarious species form relationships of dominance–subordination that are established and maintained through agonistic behavior. The social status thus established and held is related to different stress responses that have in turn been related to the development of different psychopathologies such as depression, anxiety, posttraumatic stress and substance abuse. This review of current literature looks at data on this relationship provided by experimental animal models of social stress. Social defeat provokes behavioral and neuroendocrine changes and a negative emotional state characteristic of human anxious/depressive symptomatology, which can be reversed through treatment with antidepressants. Defeated subjects show alterations in the monoaminergic systems, similar to those found in depressive patients, as well as a chronic activation of the HPA axis, high plasmatic corticosterone and CRF levels in some areas of the brain and alterations in the balance of central glucocorticoid receptors. Social stress owing to subordination induces changes in the central dopaminergic activity that may make individuals more vulnerable to drug abuse. On the other hand, aggressive behavior in dominant individuals can turn into pathological, related with a reduced brain serotonergic activity. Behavior of dominant subjects in the Reduction of Dominant Model is similar to some behavioral features of patients suffering mania.