Situation to date:
Although individuals suffering from schizophrenia show an elevated risk of violence compared to the general population, limited effort has been made to inquire the neurobiological aetiology of such behaviour. Currently, the understanding of the biological foundation of emotions in people with schizophrenia and a history of violence is limited, and the existing literature does not allow to conclude that specific deficits in functional connectivity related to distinct cognitive/emotional states are involved.
A recent work, published in Frontiers in Psychiatry (Impact Factor 3.532) in February 2020 by Andràs Tikàsz and colleagues, aimed at identifying altered functional connectivity within the emotional-salience brain network during negative emotion processing. The study compared men suffering from schizophrenia with a history of violence to those without a history of violent behaviour and healthy controls.
Hypothesizing an impaired fronto-limbic functional connectivity in people suffering from schizophrenia with a history of violence, the investigators scanned 39 men suffering from schizophrenia (20 with a history of violence and 19 without), and 21 healthy men using Functional Magnetic Resonance Imaging (fMRI) while showing them negative images. These images induced an increased connectivity between the dorsal anterior cingulate cortex (dACC) and the bilateral rostral prefrontal cortex (rPFC), as well as a decreased functional connectivity between the frontal regions (bilateral rPFC and dACC), the putamen and the hippocampus in men with schizophrenia and a history of violence. Simultaneously, the centrality of the dACC within the network was reduced in subjects with schizophrenia and a history of violent behaviour.
These results provide a more global picture of the brain functionality alterations during negative emotion processing in men with schizophrenia and a history of violence, suggesting an inefficient integration of the information by the dACC between frontal and limbic regions in violent schizophrenic patients during negative emotion processing. This highlights the importance of the ACC in the neurobiological foundations of violent behaviour in schizophrenia.
Despite some limitations, including the ongoing antipsychotic medications, the lack of a comparison group of non-psychotic subjects reporting a history of violence, the missing assessment of psychopathy, and the impossibility to infer direction and causality in the connectivity, this study sets itself as the first to characterize the alterations in functional connectivity and related topological changes of the emotional-salience network during the processing of negative emotion among men with schizophrenia and a history of violence.
Further studies are needed to characterize the direction of the connectivity alteration, while considering specific discrete emotions like anger.
The article full text is available at:
Tikàsz A, Potvin S, Dugré JR, Fahim C, Zaharieva V, Lipp O, Mendrek A, Dumais A. Violent Behavior Is Associated With Emotion Salience Network Dysconnectivity in Schizophrenia. Front Psychiatry 2020; 11: 143. doi: 10.3389/fpsyt.2020.00143