Revista de Estudios Sociales

rev. estud. soc. | eISSN 1900-5180 | ISSN 0123-885X

Is Psychopathology Related to Terrorism? A Systematic Review of the Available Evidence on Group-Based and Lone Actors

No. 96 | 2026-05-29
  • Victoria Espejo Márquez
    Ayuntamiento de Ronda, Spain
  • Miguel A. Maldonado
    Universidad de Córdoba, Spain
    ORCID iD: https://orcid.org/0000-0002-9126-2596
  • Roberto M. Lobato
    Universidad de Burgos, Spain
    ORCID iD: https://orcid.org/0000-0003-4152-7020
  • Manuel Moyano Pacheco
    Universidad de Córdoba, Spain
    ORCID iD: https://orcid.org/0000-0001-6745-0936
https://doi.org/10.7440/res96.2026.09

Abstract

Over the past two decades, research on terrorism has expanded considerably. Within this field, one central line of inquiry concerns the factors associated with this form of violence, and the relationship between psychopathology and terrorism has emerged as one of the most debated topics. Early studies largely concentrated on individuals operating within organizations. More recently, however, the rise of lone actors has led to growing scholarly attention to this group. Identifying whether mental disorders differentiate collective actors from individuals acting alone would be valuable for prevention and counterterrorism. This systematic review seeks to bring together existing evidence on the prevalence of mental disorders among individuals involved in terrorist activities, both within groups and as lone actors, and to examine whether differences between these two categories can be observed in this regard. The PRISMA method guided the selection and analysis of twenty articles. The review compiles data on diagnosed disorders, psychopathological traits, and related symptoms, along with other indicators such as hospitalizations linked to these diagnoses. Overall, the findings indicate that rates of psychopathology among individuals engaging in behaviors associated with terrorism tend to fall within ranges similar to those reported in population studies. At the same time, some research points to higher prevalence in certain subgroups, particularly among lone actors. Comparisons between group-based and lone actors yield uneven results: although some studies suggest a higher presence of disorders and psychopathological traits among lone actors, findings vary across the literature and no clear consensus has been reached. Taken together, the results underscore the need for further research into the role of psychopathology in terrorist behavior, as well as its implications for prevention and early detection. 

Keywords: extremism, mental disorder, mental health, psychiatry, psychopathology, terrorism

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