tDCS targeting the Ventromedial Prefrontal Cortex reduces reactive aggression and modulates electrophysiological responses in a forensic population.

Abstract

BACKGROUND\nStudies have shown that impairments in the ventromedial prefrontal cortex (vmPFC) in forensic patients who also abuse cocaine and alcohol, play a crucial role in violent behavior. Moreover, interventions that aimed to reduce violence risk in those patients are found not to be optimal. A promising intervention might be to modulate the vmPFC by high-definition (HD) transcranial Direct Current Stimulation (tDCS). The current study aimed to examine (HD)-tDCS as an intervention to increase empathic abilities and reduce violent behavior in forensic substance dependent offenders. In addition, using electroencephalography (EEG), we examined the effects on the P3 and the Late Positive Potential (LPP) of the Event-Related Potentials (ERPs) in reaction to situations that depict victims of aggression.\n\n\nMETHODS\nFifty male forensic patients with a substance dependence were tested in a double-blind sham-controlled randomized study. The patients received HD-tDCS two times a day for 20\u2009min for five consecutive days. Before and after the intervention, the patients completed self-reports, performed the Point Subtraction Aggression Paradigm (PSAP), and EEG was recorded while patients performed an empathy task.\n\n\nRESULTS\nResults showed a decrease in aggressive responses on the PSAP and in self-reported reactive aggression in the active tDCS group. Additionally, we found a general increase in LPP amplitude after active tDCS. No effects on trait empathy and the P3 were found.\n\n\nCONCLUSIONS\nCurrent findings are the first to find positive effects of HD-tDCS reducing aggression and modulate electrophysiological responses in forensic patients, showing the potential of using tDCS as an intervention to reduce aggression in forensic mental healthcare.