There is an increased risk of violence in individuals with clinical depression, researchers say.

A diagnosis of depression increases the risk of committing violent crime three-fold, research has shown.

The study of nearly 50,000 people in Sweden found that 3.7 per cent of men and 0.5 per cent of women committed a violent crime after being identified as clinically depressed.

This compared with 1.2 per cent of men and 0.2 per cent of women in the general population.

Lead author Professor Seena Fazel, from the Department of Psychiatry at Oxford University, said: "We wanted to determine whether there was an increased risk of violence in individuals with clinical depression, and without other factors which are known to contribute to this risk.

"One important finding was that the vast majority of depressed persons were not convicted of violent crimes, and that the rates reported are below those for schizophrenia and bipolar disorder, and considerably lower than for alcohol or drug abuse.

"Quite understandably, there is considerable concern about self-harm and suicide in depression. We demonstrate that the rates of violent crime are at least as high, but they don't receive the same level of attention in clinical guidelines or mainstream clinical practice."

The researchers tracked the medical records and conviction rates of 47,158 people diagnosed with depression over a period of about three years. They compared that data with the records of 898,454 people with no history of depression.

People diagnosed with depression were both more likely to harm themselves and others than members of the general population.

Violent crime was defined as a conviction for any of the following offences: homicide or attempted homicide, aggravated or common assault, robbery, arson, sexual offences (including indecent exposure, and illegal threats or intimidation).

When the researchers took account of previous histories of violence, self-harm, psychosis, and substance misuse they still found a link between depression and violent crime. However, the risk was smaller.

Marjorie Wallace, chief executive of the mental health charity Sane, said: "The majority of people with depression are never violent, yet people receiving a diagnosis can feel frustrated, angry and initially desperate.

"It is also very rare for anyone with depression to commit crime. This study does however show how important it is for professionals not to ignore those strong feelings and make clear people can come to terms with how they feel and recover."