We test whether significant differences in mental illness exist in a matched sample of lone-and group-based terrorists. We then test whether there are distinct behavioral differences between lone-actor terrorists with and without mental illness. We then stratify our sample across a range of diagnoses and again test whether significant differences exist. We conduct a series of bivariate, multivariate, and multinomial statistical tests using a unique dataset of 119 lone-actor terrorists and a matched sample of group-based terrorists. The odds of a lone-actor terrorist having a mental illness is 13.49 times higher than the odds of a group actor having a mental illness. Lone actors who were mentally ill were 18.07 times more likely to have a spouse or partner who was involved in a wider movement than those without a history of mental illness. Those with a mental illness were more likely to have a proximate upcoming life change, more likely to have been a recent victim of prejudice, and experienced proximate and chronic stress. The results identify behaviors and traits that security agencies can utilize to monitor and prevent lone-actor terrorism events. The correlated behaviors provide an image of how risk can crystalize within the individual offender and that our understanding of lone-actor terrorism should be multivariate in nature.

No abstract

For the past forty years, researchers studied the relationship between mental disorder and terrorist involvement. The literature developed in four paradigms, each of which differs in terms of their empirical evidence, the specific mental disorders studied, and their conceptualizations of terrorist involvement. These paradigms have not, however, witnessed linear and incremental improvements upon one another. Although one paradigm has generally tended to dominate a temporal period, many false assumptions and incorrect interpretations of earlier work permeate into today's discourse. This paper provides a history of the study of mental disorders and the terrorist. First, we briefly outline the core fundamental principles of the first two paradigms, The paper then outlines the core arguments produced by the seminal reviews conducted in paradigm three. We highlight how these findings were consistently misinterpreted in subsequent citations. We then highlight recent innovations in the study of terrorism and mental disorder since the various influential literature reviews of 1997-2005. We conclude by outlining how future research in this area may improve in the coming years by broadening our understanding of both terrorist involvement and psychopathology away from simple dichotomous thinking.

This paper outlines the sociodemographic, developmental, antecedent attack, attack preparation, and commission properties of 115 mass murderers between 1990 and 2014. The results indicate that mass murderer attacks are usually the culmination of a complex mix of personal, political, and social drivers that crystalize at the same time to drive the individual down the path of violent action. We specifically focus upon areas related to prior criminal engagement, leakage, and attack location familiarity. Whether the violence comes to fruition is usually a combination of the availability and vulnerability of suitable targets that suit the heady mix of personal and political grievances and the individual's capability to engage in an attack from both a psychological and technical capability standpoint. Many individual cases share a mixture of unfortunate personal life circumstances coupled with an intensification of beliefs/grievances that later developed into the idea to engage in violence.

Research Summary

To move beyond current aggregate and static conclusions regarding radicalisation and subsequent terrorist behaviour, empirical research should look to criminological models which are influenced by the life course perspective.Current UK government policy designed to prevent radicalisation and terrorist engagement look to outputs from criminological perspectives to inform policy and practice. However, the guidance suffers from a lack of specificity as to the major concept of 'vulnerability to radicalisation', and what this incorporates. This investigation uses sequential analyses to add to our understanding of 'vulnerability' in the specific context of lone-actor terrorism. The statistical method bridges the gap between qualitative and quantitative approaches and provides a series of empirical outputs which visualise typical lone-actor terrorist trajectories through the discrete stages of radicalisation, attack planning and attack commission.

A wide range of studies investigating the nature and determinants of radicalisation, and terrorist-related behaviour exist. These, in turn, have influenced theory, policy and practice in areas concerned with violent extremism prevention, disruption and management. As such interventions become more common, debates rage within mental health professions about the role mental health practitioners should play in countering violent extremism. This systematic review assesses the impact of mental health problems upon attitudes, intentions and behaviours in the context of radicalisation and terrorism. We identified 25 studies that measured rates of mental health problems across 28 samples. The prevalence rates are heterogenous and range from 0% to 57%. If we pool the results of those samples (n=19) purely focused upon confirmed diagnoses where sample sizes are known (n=1705 subjects), the results suggest a rate of 14.4% with a confirmed diagnosis. Where studies relied upon wholly, or in some form, upon privileged access to police or judicial data, diagnoses occurred 16.96% of the time (n=283 subjects). Where studies were purely focused upon open sources (n=1089 subjects), diagnoses were present 9.82% of the time. We then explore (a) the types and rates of mental health disorders identified (b) comparison/control group studies (c) studies that explore causal roles of mental health problems and (d) other complex needs.

Objectives This paper utilizes probability-based modelling to unpack the complex and multifaceted individual, sociological, and psychological processes present within terrorist groups which may affect an individual's psychological wellbeing. We outline the predictors of the onset of psychological distress across three phases of terrorist involvement (engagement, disengagement, and post-disengagement). Methods Utilizing a dataset of over 90 terrorist autobiographies, we conduct sequence analyses to pinpoint the onset of psychological problems and the experiences that preceded and proceeded this onset. Results The results demonstrate the complexity in the relationship between mental disorders and terrorist engagement and the heterogeneity of the lived experience of 'being' a terrorist. The experience of psychological distress is mediated by numerous factors and the combination of these factors. Conclusions The results helped highlight the complexity of 'being' a terrorist; multiple factors at individual, social, and group levels impact on an individual as they pass through life. Individuals engaged within terrorism encounter a number of risk factors, which if an individual has lower baseline levels of individual resilience and is not fully committed to the group identity, may impact them psychologically. The results highlighted that it is not the presence of risk factors which impact on an individual, but how they perceive these risk factors.