The MacArthur Violence Risk Assessment Study followed a group of 1,136 patients who had been discharged from acute civil inpatient facilities at three U.S. sites between 1992 and 1995. This sample included English-speaking male and female patients who were between the ages of 18 and 40; were of white, African-American, or Hispanic background; and had a chart diagnosis of bipolar disorder, depressive disorder, schizophrenia or other psychotic disorder, substance use disorder, or personality disorder.
Three sources of information were used to ascertain the occurrence of violent acts in the community post discharge, including interviews with patients, interviews with persons identified by the patient as being knowledgeable about his or her life, and official sources of information (arrest and hospital records).
Of the 951 persons available for at least one follow-up, 23 (2%) committed acts of violence with a gun. These 23 people tended to have admission diagnoses of major depression (61%), alcohol abuse (74%), or drug abuse (52%). Three patients (13%) were diagnosed as having bipolar disorder, none were diagnosed as having schizophrenia, and three (13%) received other diagnoses. At the time of hospital admission, the 23 people who later went on to commit gun violence displayed symptoms of substance abuse (61%), suicidal threats (65%), hallucinations (22%), paranoia (13%), delusions (9%), and anxiety (9%).
While prior hospitalization rates among discharged patients who committed gun violence were comparable to those of the overall MacArthur sample in the study (78% and 73%, respectively), the prior arrest rate of discharged patients who later committed gun violence was almost twice as high as the prior arrest rate of the overall sample (89% and 49%, respectively).
“For the small group of people with mental illness who are at risk of committing gun violence, improved collaborations with the criminal justice system are clearly indicated,” the researchers stated. “However, directly targeting mental illness as the major driver of gun violence is misguided. ... Prior violence, substance use, and early trauma are more likely to contribute to subsequent violence than is mental illness per se. In this regard, the politically inspired haste to focus gun control efforts on people being treated for a mental illness, rather than on people with demonstrated indicators of violence risk, such as restraining orders related to domestic violence, seems particularly misdirected.”
For more on this subject, see the Psychiatric News article "Capitol Hill Gets Straight Story on Gun Violence, Mental Illness."