Caroline Helwick

December 05, 2014

NEW ORLEANS — A survey of school shootings in the United States revealed that only 17% of the perpetrators had a diagnosis of mental illness, but several risk factors emerged that could have served as warning signs.

"We found that in 73 of the 157 incidents, there was evidence of one or more risk factors," said Janice Hill-Jordan, PhD, from Southern Illinois University School of Medicine in Springfield. "Those are warning signs; they are things we can see in children that should make us think."

Dr. Hill-Jordan and her colleague, Ayame Takahashi, MD, also from the Southern Illinois University School of Medicine, presented their findings here at the American Public Health Association 142nd Annual Meeting.

A previous study from the US Secret Service and the Department of Education identified 37 incidents from 1974 to 2000, involving 41 attackers. An analysis of the shooters found that only one-third had a mental health evaluation, and only 20% had received a diagnosis of mental illness. Those numbers are similar to the current findings, Dr. Takahashi reported.

In their study, Drs Hill-Jordan and Takahashi identified 157 school shooting incidents from 2005 to 2012, involving 403 students. During the 7-year period, 146 students were killed, 29 more committed suicide, 222 were wounded, and 6 were shot by police.

The researchers used information gleaned from Internet news sources, and they looked for factors correlating with these incidents.

They defined a school shooting as one that took place on school property or at a school-sponsored event, regardless of the number of victims. The presence of mental illness was assumed if evidence came from a credible source, such as if a family member reported a diagnosis, if the patient had been prescribed psychotropic medications, if a legal document contained this information, or if there was evidence of "bizarre thinking" or suicidal thoughts from a Facebook page or diary.

In 97% of the cases, the shooter was male. Mean age was 17 years and median age was 22 years. Most of the shooters were white (50%), 38% were black, 5% were Hispanic, and 7% were other. The vast majority, 79%, were committed by one shooter. In 52% of cases, the site was a high school.

The most common motivating factors were an argument or fight (22%), gang-related or other crime (20%), and stalking or intimate partner violence (10%).

Nearly Half the Shooters Had Risk Factors

The researchers found evidence of a mental illness in only 17% of shooters. Dr. Hill-Jordan said she believes this low number reflects incomplete data, especially for incidents not considered "rampages." Many details are missing in such cases because "we don't have access to data on their mental health," she pointed out.

Nearly half the shooters, however, had demonstrated a warning sign associated with violence. These included racism, Nazism, gay bashing, gang membership, previous encounters with the law, poor grades, anger at school personnel or suspension, being bullied or being a bully, obsession with the Columbine shooting, parental mental health problems, and family troubles.

In a bivariate analysis, several factors emerged as significant when they occurred in conjunction with a diagnosis of mental illness. Students with a diagnosis of mental illness were significantly more likely to also commit suicide and to obtain the weapon from their own home or father.

The data suggest that cumulative effects led to the incident. "Arguments are being made for increased access to mental health, for changing the culture in schools, for reducing access to guns, but it's not one thing. Our research shows that we need to do all of the above," Dr. Takahashi said.

Five elements have been identified as contributing to school shootings, the researchers report. These are gun availability, a cultural script that supports a school shooting in the student's mind, the perception of an extremely marginal social position within a environment that is important to the student, an individual problem that magnifies the impact of the shooter's social marginalization (family problems, abuse), and the failure of social support systems designed to identify troubled children.

A Critical Look at Mental Illness

One person who attended the presentation suggested that the movement to secure school buildings might be counterproductive. "Going into a school with metal detectors, bag checks, and security walking the hallways has got to have a negative effect. What is this doing for our young people?"

Dr. Takahashi explained that some schools have made efforts to increase communication about problems by hiring safety officers. The position is not so much to police as to be a designated place for students to talk to adults about any concerns they might have.

A more critical look at the mental illness category is needed, said Melissa Dupont-Reyes, MPH, from Columbia University in New York City.

The shooting incident could be the mental break that is needed for the diagnosis.

Mental illness is an umbrella term for many conditions, but only psychosis is truly dangerous. "You could benefit from distinguishing psychosis from bipolar, schizophrenia, depression, and so forth," Dr. Dupont-Reyes pointed out.

The low number of established cases of mental illness is not surprising, said Jim May, PhD, from the Richmond Behavioral Health Authority in Virginia.

"You don't get labels such as bipolar illness or schizophrenia easily. Usually, something major has to happen to trigger this diagnosis, which frequently comes in the teens and mid-20s," he told Medscape Medical News.

"It's more accurate to say the shooters had no history of mental illness. The shooting incident could be the mental break that is needed for the diagnosis," Dr. May pointed out.

"This dataset is a bit thin at this point for making predictive comments," he added, "but the more data we can get, the better."

"I am convinced that if we have enough data — and 'big data' from broad sections of research could help — we could start to be predictive, and we could educate ourselves as professionals and the community better," Dr. May explained. "Our center is taking some mental health 'first aid' and suicide prevention training into the community, and we have been pleasantly surprised at how much the community wants this information."

There was no commercial funding for this study. Dr. Hill-Jordan, Dr. Takahashi, and Dr. May have disclosed no relevant financial relationships.

American Public Health Association (APHA) 142nd Annual Meeting. Abstract 304213. Presented November 18, 2014.


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