Over half of the perpetrators were found to have schizophrenia, with psychotic symptoms including the belief they were receiving messages from demons and seeing hallucinations ordering them to “kill, burn or destroy.“
Researchers from the Stanford University School of Medicine have published a study that reveals most of the perpetrators of mass shootings in America are people with undiagnosed psychiatric disorders.
The study focused on 115 assailants of shootings committed between 1982 and 2019, and then narrowed that number down to ones who survived.
“We found that most mass shooters in our study experienced undiagnosed and unmedicated psychiatric illness,” the researchers noted.
Describing the findings as “striking,” the study notes that symptoms of clinical psychiatric disorders were identified in almost all the shooters, 32 out of 35.
Over half of the perpetrators, 18, were found to have schizophrenia, with psychotic symptoms including the belief they were receiving messages from demons and seeing hallucinations ordering them to “kill, burn or destroy.”
A further 10 of the shooters were diagnosed as bipolar, delusional and suffering from personality disorders.
The study also noted that “None were medicated or received other treatment prior to the crime.”
To make the diagnoses, the study focused on the records of forensic psychiatrists and court proceedings, in addition to writings and social media posts made by the shooters.
Researchers also found that in 20 mass shooting cases where the perpetrators died, at least eight had schizophrenia, seven had other diagnoses, and five had unknown mental illnesses.
While concluding that diagnosis and treatment of mental illness could have “decreased violence,” the study notes that “Psychiatric research… on the nature and the incidence of mental illness among mass shooters, however, remains largely understudied.”
“Most of the cases of domestic mass murders possibly might have been prevented had the assailant… been more consistently assisted to receive a correct diagnosis… followed by psychiatric medication treatment… to save lives,” the study suggests.