Shared brain basis of aggression in clinical, forensic, and healthy samples: A meta-analysis

Background Aggression, violence, and antisocial behaviour constitute a large-scale societal problem. Aggression is common in incarcerated offenders and psychiatric conditions, but also healthy and noninstitutionalized populations vary in violent and aggressive behaviour. The brain basis of aggression has been studied extensively in the past, but the similarities between criminal, pathological and everyday aggression in the brain remain elusive. Methods We conducted an activation likelihood estimation (ALE) meta-analysis of 406 neuroimaging studies with 28 968 subjects using structural magnetic resonance imaging (MRI), functional magnetic resonance imaging (fMRI), positron emission tomography (PET) and single photon emission tomography (SPECT). The included studies had either i) measured haemodynamic responses during aggression-related functional tasks, ii) compared the brain structure, molecular organization, or function between aggressive forensic and psychiatric populations and control groups, or iii) addressed the effects of trait aggression on brain structure or function. Results Aggression was consistently associated with altered function and structure in the amygdala, hippocampus, basal ganglia, anterior cingulate cortex, and the dorsolateral and orbitofrontal cortices. Functional coactivation analysis suggested that these regions are most consistently associated with emotional and reward function as well as their regulation. The results were comparable in healthy subjects as well as forensic and psychiatric populations. Conclusions Aggression is linked with alterations in multiple neurocognitive systems forming a common network for aggressiveness. Particularly the neural systems implicated in reward, emotions and regulation were commonly associated with aggression. The established network is involved in the whole continuum of aggression from benign variations in healthy volunteers to forensic subjects and violent clinical populations, suggesting a common aggression network whose severe perturbations may be linked with criminal behaviour or pathological aggression.