Factors that put mentally ill at risk of violent behaviour

These risk factors, according to the study, are if an individual is currently using alcohol; if an individual has engaged in violent behaviour over the past six months; and if an individual has been a victim of violence within the past six months.

Violent behaviour, in this context, ranged from pushing and shoving to sexual assault and assault with a deadly weapon.

"We found that these risk factors were predictive even when we accounted for age, sex, race, mental illness diagnosis and other clinical characteristics," said study co-author Sarah Desmarais, associate professor of psychology at North Carolina State University in the US.

The findings, published in the journal Psychiatric Services, give mental health professionals and others working with adults with mental illness a suite of characteristics they can use as potential warning signs, allowing them to intervene and hopefully prevent violent behaviour.

The researchers compiled a database of 4,480 adults with mental illnesses - including schizophrenia, bipolar disorder and depression - who had answered questions about both committing violence and being victims of violence in the previous six months. 

The database drew from five earlier studies that focused on issues ranging from antipsychotic medications to treatment approaches. 

Those studies had different research goals, but all asked identical questions related to violence and victimisation.

The researchers assessed the data to determine which behaviours, events and characteristics were most predictive of violent behaviour over a six-month period.