The hallucinations and delusions associated with psychosis seldom foreshadow acts of violence, according to new research led by the University of California, Berkeley.
The findings, published in the online journal Clinical Psychological Science, challenge the media-fueled stereotype of psychosis-induced aggression.
For the study, researchers conducted a meticulous review of 305 violent incidents by mental health patients in the United States, and discovered that only 12 percent of these were preceded by psychosis.
Numerous studies have shown that violence and murder are more likely to be sparked by anger, access to firearms, and substance abuse. The new study is the first to analyze the regularity of psychosis-induced violence among the mentally ill.
“High-profile mass shootings capture public attention and increase vigilance of people with mental illness. But our findings clearly show that psychosis rarely leads directly to violence,” said study lead author Dr. Jennifer Skeem, a clinical psychologist and associate dean of research at University of California, Berkeley’s School of Social Welfare.
Skeem and fellow researchers at the University of Virginia and Columbia University focused on the most violent patients tracked in the MacArthur Violence Risk Assessment study, a major 1998 analysis of more than 1,100 offenders who had been discharged from psychiatric facilities.
Specifically, the researchers focused on 100 high-risk patients, who had been involved in two or more violent incidents in the year after they were discharged from a psychiatric facility. The goal was to establish their mental states at the time they were engaging in acts of violence.
“We wanted to examine the small group of people with repeated violence and see how consistently these violent incidents were caused by hallucinations and delusions,” Skeem said.
In addition to reviewing records, they interviewed former patients about what they were thinking and feeling just before they committed acts of violence, and also sought the perspectives of their friends and family members.
The findings revealed that psychosis preceded only 12 percent of the violent acts they committed following their release. Furthermore, if psychosis was the basis of one violent incident, it was rarely implicated in subsequent ones.
Mental health professionals and advocates assert that high-profile cases perpetuate the stigma of mental illness, and keep people who are suffering from psychiatric disorders from talking about their condition and seeking help.
In fact, they say, people with mental illness are more likely to be victims of violence than the perpetrators.
“None of this detracts from the message that people with mental illness need access to psychiatric services,” Skeem said.
“But it’s important to remember that risk factors for violence, such as substance abuse, childhood maltreatment, neighborhood disadvantage, are mostly shared by people with and without mental illness, and that’s what we should be focused on if maximizing public safety is our goal.”