Extremism, Terrorism, and Mental Disorder

Focus (Am Psychiatr Publ). 2026 Jan;24(1):53-58. doi: 10.1176/appi.focus.20250033. Epub 2026 Jan 15.

ABSTRACT

The nexus between mental disorder and terrorism has long confounded both clinicians and researchers. Data indicate that approximately one-third of lone-actor terrorists will be diagnosed as having a mental disorder on clinical interview, but members of a terrorist group typically have neither more nor less mental disorder diagnoses than the general population. Other notable problems for the psychiatrist are distinguishing between symptoms of mental disorder and extremist beliefs, discerning radicalization and a pathway to violence in a psychiatric patient, and identifying the proximal warning behaviors that suggest a heightened probability of violence toward a targeted individual or group. Steps toward clarification of these various issues through measurement and mitigation of risk are offered.

PMID:41953874 | PMC:PMC13003250 | DOI:10.1176/appi.focus.20250033