In total, eight studies were included, of which only two studies distinguished prevalence rates and types of psychopathology separately for women, indicating personality disorder as most common. All four out of the eight studies that reported on the relationship between psychopathology and terrorism and violent extremism assumed psychopathology to be a contributing factor in engaging in terrorist or violent extremist acts.  

 Some research suggests high rates of psychiatric disorders in subgroups of radicalized people and lone-actor terrorists.  

 Radicalization is a process, by which individuals adopt extreme political, social and religious ideation that leads to mass violence acts. It has been hypothesized that mental health characteristics might be associated with a risk of radicalization.