Offenders 'should be routinely checked for signs of past head injuries'
More than half of prisoners could have head injuries that may be behind their offending, a review has found.
Experts from the universities of Exeter, Manchester, Oxford, Glasgow and Sheffield, along with the Centre for Mental Health, are now calling for all offenders to be screened for traumatic brain injuries.
Such injuries are linked to greater violence and problems in prison, and the researchers say that better support could reduce the likelihood of offending or re-offending.
The team reviewed existing evidence and concluded that young people with traumatic brain injuries are at a greater risk of early, more violent offending.
They believe this may be because such injuries can compromise the neurological functions for self-regulation and social behaviour, and increase risk of behavioural and psychiatric disorders.
Young offenders with traumatic brain injuries are particularly at risk of self-harm and suicidal behaviour, the review found.
"Addressing traumatic brain injury offers a means to not only improve the lives of those who offend, but also to reduce crime," Professor Huw Williams, of the University of Exeter.
"A range of measures could reduce the risk of crime following traumatic brain injury.
"These could include any form of neurorehabilitation, and better links between emergency departments, community mental health services, GPs and school systems that might lead to early identification and management of traumatic brain injury in children and young people, particularly in areas of socioeconomic deprivation.
"On a person's entry into the justice system, there is an opportunity to deliver routine screening for traumatic brain injury and provision of treatment options.
"Another beneficial step could be brain injury link-workers in prisons to enable screening and support for those with traumatic brain injury."
Traumatic brain injuries result from serious blows to the head that cause permanent brain changes, such as assaults, falls or a car crash.
A very mild injury - typically referred to as a concussion - rarely leads to traumatic brain injury.
Increased severity of injury results in a higher risk of chronic problems.
Research suggests that the lifetime costs are £155,000 for a person aged 15 with a mild or moderate traumatic brain injury - £95,000 in healthcare costs and £60,000 for the costs of additional offending.
The figures are much higher for those already in the criminal justice system.
The review found between 10-20% of people in custody have "complicated mild traumatic brain injury or moderate to severe head injury", with a further 30-40% having milder traumatic brain injuries.
Researchers estimate that the risk of earlier, more violent offending more than doubles in people with traumatic brain injuries.
Their paper is published in The Lancet Psychiatry.