Neuropsychiatry of frontal lobe dysfunction in violent and criminal behaviour: a critical review

Objectives-To establish the link between frontal lobe dysfunction and viole nt and criminal behaviour, based on a review of relevant literature. Methods-Articles relating evidence of frontal lobe dysfunction with violenc e or crime were collected through a MEDLINE search using the keyword "front al lobe" combined with the terms "aggression," "violence," "crime," "antiso cial personality disorder," "psychopathy," "impulse control disorders", and "episodic dyscontrol." Reference lists were then searched for additional a rticles. Results-High rates of neuropsychiatric abnormalities reported in persons wi th violent and criminal behaviour suggest an association between aggressive dyscontrol and brain injury, especially involving the frontal lobes. The s tudies reviewed support an association between frontal lobe dysfunction and increased aggressive and antisocial behaviour. Focal orbitofrontal injury is specifically associated with increased aggression. Deficits in frontal e xecutive function may increase the likelihood of future aggression, but no study has reliably demonstrated a characteristic pattern of frontal network dysfunction predictive of violent crime. Conclusions-Clinically significant focal frontal lobe dysfunction is associ ated with aggressive dyscontrol, but the increased risk of violence seems l ess than is widely presumed. Evidence is strongest for an association betwe en focal prefrontal damage and an impulsive subtype of aggressive behaviour .