Only 1 in 5 murderers are psychotic
Though it is true that many mass murderers are diagnosed with severe mental illness, only one in five are likely psychotic or delusional, according to Dr Michael Stone, a forensic psychiatrist. He maintains a database of 350 mass killers going back more than a century, writes Benedict Carey, a science reporter for The New York Times
Analysing his database, Dr Stone has concluded that about 65 per cent of mass killers exhibited no evidence of a severe mental disorder; 22 per cent likely had psychosis and the remaining had depressive or antisocial traits, Carey adds
Stress a reason?
Similarly, a 2016 analysis of 71 lonewolf terrorists and 115 mass killers by the Department of Justice echoed Dr. Stone’s findings. The overall rate of psychiatric history, including depression and other learning disabilities, was 48 per cent. But a greater percentage (67 per cent) faced long-term stress
Using both studies, forensic psychologist J Reid Meloy has identified what he calls a “paranoid spectrum”. At the extreme end of the spectrum are people diagnosed with psychosis. The majority are not deeply ill, but are “injustice collectors” prone to perceiving insults or failures as a form of persecution, and often blame them on an individual or a group. And some of them might act on it