Identifying Neuro-Genetic Risk and Protective Factors for Violence and Aggression: Filling the Gap between Incarcerated Offenders and Community Population

Background:Violence and aggression not only bring tremendous cost to victim andaggressor but also result in an extreme financial and emotional burden onthe entire society. More than one-third of estimated total nursing costper ward per year was connected to managing violence and aggression.Although there was abundant neuro-biological evidence indicating thebrain and neuro-genetic abnormality in incarcerated psychopathic-offenders and subjects with aberrant psychopathological-traits, such asconduct disorder, anti-social, and callous–unemotional traits, the gapbetween incarcerated/or psychologically ill samples and normal communitypopulation left a weak external validity to possibly prevent and controlthe potential violence. The goal of this study is to identify the neuro-genetic risk and protective factors among normal community samples bycombining multiple levels of analysis including electrophysiological,behavioral, genetic, neuro-hemodynamic, and brain structure measures.Specific Aims:[1]To identify neuro-genetic risk factors for psychopathic traits amongnormal community samples[2]To examine neural mechanism mediating the genetic risk for theviolence and aggression[3]To examine the protective effect of morality and empathy in themoderation of the linkage between psychopathic traits and elevatedaggressionMaterials and Methods:This three-year project will recruit 250 healthy adults for each year.The sample size is determined by careful calculation in order to achieveadequate power for genetic association. Participants take part in thebehavior tasks and then receive the MRI scanning. The behavioralmeasurements include the Justice Sensitivity Inventory, ImplicitAssociation Test of Morality, Psychopathic Personality Inventory, Tayloraggression paradigm, Interpersonal Reactivity Index for empathy, and thedigit ratio (2D: 4D) for the measure of prenatal sex-hormones priming.Genotypes of selected genes [Monoamine oxidase A (MAOA) and Serotonintransporter 5-HTTLPR] are based on previous literatures. The DNA wasextracted from buccal swabs using a QIAmp DNA Mini Kit. Participantsreceive brain structure examination including Diffusion Tensor Imagingand Voxel-based morphometry as well as functional connectivity ofResting state functional brain imaging for the first year. Participantsreceive fMRI scanning while being on-line measured the aggressivebehaviors under provoking vs non-provoking condition with a variant ofthe Taylor aggression paradigm (TAP) for the second year, and makingmoral judgments at the third year.Anticipated Results:Based on our preliminary data, we anticipate that (1) reduced guiltyfeelings and moral motivation is associated with psychopathic traitsamong normal community samples; (2) psychopathic traits in normalcommunity samples predict degree of aggressiveness; and (3) morality andempathy serve as protective factors to moderate the linkage betweenpsychopathic traits and elevated aggression. We ought to identify theneuro-genetic risk and protective factors for psychopathic traits andviolence among normal community samples and hence offer potentialgaining of new insights into the underlying neurobiological and geneticmechanisms of violence, enabling translation towards therapeutic andpharmacological interventions.