Mental illness and terrorism There is little evidence supporting the concept of mental illness as a part of, or reason behind radicalization towards violent extremism and terrorism. There is weak evidence that lone gunmen, particularly those involved in school shootings, may suffer from mental illness to a larger degree than the general population, whereas organized terrorist groups such as jihadists and right-wing extremists seem to avoid mentally unstable individuals. Clinical use of the instruments developed for screening and risk assessment of individuals suspected of radicalization towards violent extremism will compromise the trust placed in the Swedish health care system by the citizens it is there to serve. The usage of empirically grounded risk assessment instruments should be restricted to forensic psychiatric clinics. Individuals at risk of radicalization towards violent extremism who present signs and symptoms of mental illness should be offered psychiatric treatment.