Aggression, Aggression-Related Psychopathologies and Their Models

Abstract

Neural mechanisms of aggression and violence are often studied in the laboratory by means of animal models. A multitude of such models were developed over the last decades, which, however, were rarely if ever compared systematically from a psychopathological perspective. By overviewing the main models, I show here that the classical ones exploited the natural tendency of animals to defend their territory, to fight for social rank, to defend themselves from imminent dangers and to defend their pups. All these forms of aggression are functional and adaptive; consequently, not necessarily appropriate for modeling non-natural states, e.g., aggression-related psychopathologies. A number of more psychopathology-oriented models were also developed over the last two decades, which were based on the etiological factors of aggression-related mental disorders. When animals were exposed to such factors, their aggressiveness suffered durable changes, which were deviant in the meaning that they broke the evolutionarily conserved rules that minimize the dangers associated with aggression. Changes in aggression were associated with a series of dysfunctions that affected other domains of functioning, like with aggression-related disorders where aggression is just one of the symptoms. The comparative overview of such models suggests that while the approach still suffers from a series of deficits, they hold the important potential of extending our knowledge on aggression control over the pathological domain of this behavior.

Understanding the Role of Oxidative Stress, Neuroinflammation and Abnormal Myelination in Excessive Aggression Associated with Depression: Recent Input from Mechanistic Studies

“…Aggression comprises a suite of agonistic behavioural interactions; thus, various species-specific relevant signals, including danger and emotional stressors, are transduced by sensory afferents to the central nervous system (CNS) where this information is processed by the limbic neurocircuitry [ 99 , 100 ]. Data from animal and human studies suggested several key brain regions, primarily in the limbic system, associated with aggression and depressive syndromes [ 101 ].…”

“…The amygdala is generally regarded as a key brain structure regulating aggressive behaviour [ 101 , 102 , 103 ]. It mediates fear and defensive responses [ 104 ] and is important in the processing of emotionally adverse events [ 105 ].…”

Maternal separation early in life induces excessive activity of the central amygdala related to abnormal aggression

“…Even when the intruder surrendered and became immobile, the resident with bilateral CeA activation slowly approached and bit the intruder. Thus, the aggression observed in the MS group might reflect abnormal aggression beyond the need to defend territory as defined by Haller (Haller, 2018, 2022).…”

“…Thus, the aggression observed in the MS group might reflect abnormal aggression beyond the need to defend territory as defined by Haller (Haller, 2018(Haller, , 2022.…”

Delirium during COVID‑19: A report of eight cases and a review of the literature

“…Of note, all the patients described herein manifested a hyperactive form of delirium, exhibiting verbal and physical aggressiveness towards the health workers. Verbal and physical aggressiveness towards health workers can be considered, in psychopathological terms, a form of hetero-aggressiveness or heterodirect aggressiveness, which is a feature of hyperactive delirium, that is characterized itself by an aggressive behavior, according to DSM-5 (87)(88)(89)(90). However, it is possible that some cases of hypoactive delirium have passed undiagnosed and have been resolved without the use of medications.…”