People with mental illnesses are at an increased risk of becoming the victim of a murder, a new study suggests.

According to Swedish and US scientists, while murders carried out by people with mental illnesses often get a lot of attention, their risk of being the victim has rarely been investigated.

The scientists decided to look into this further. They analysed mental disorders and murders throughout the entire population of Sweden between 2001 and 2008.

The mental disorders were divided into five categories:
-Substance use disorders
-Schizophrenia
-Mood disorders, including depression
-Anxiety disorders
-Personality disorders.

The study of more than seven million people found that at least one in five murder victims had a mental disorder.

After taking into account relevant factors, such as age, gender, education level and income, the scientists determined that those with mental disorders had a five-fold increased risk of being murdered compared to people without mental disorders.

This risk was highest among people with substance abuse issues - they had a nine-fold increased risk of being murdered.

The scientists said that one reason for this may be that people with mental illnesses are more likely to live in areas of high depravation, which generally have higher murder rates.

They may also have low awareness of risks to their safety as a result of the illness.

The scientists said that efforts to reduce such risks should include ‘collaborations between mental health clinics and the criminal justice system to develop personal safety and conflict management skills among people with mental illness'.

Other interventions could include access to substance abuse treatment, increased financial stability and better housing, they added.

Details of these findings are published in the British Medical Journal.