“Crime is a much more complex condition that is brought about by a myriad of social, environmental, personality, mental health and situational circumstances.

“Head injury is only one among many and not even a first among equals.”

Graeme Fairchild, a reader in the psychology at the University of Bath, added: “One of the main problems is that many of the risk factors for criminal offending and violence, eg. being male, coming from a low socioeconomic status background, having ADHD, being physically abused, and abusing alcohol and other substances, are also risk factors for sustaining head injuries, so it is very difficult to disentangle cause and effect here.

“Many young people sustain head injuries without going on to develop criminal behaviour.”

Peter McCabe, Chief Executive of Headway – the brain injury association, whose Justice Project calls for better screening of prisoners said: “The vast majority of people who sustain a brain injury will not be involved with the criminal justice system.

“However, some of the effects of brain injury, such as memory loss, increased impulsivity, anger, and reduced inhibition can lead people into difficulty with the law and evidence suggests over representation of brain injury in offender populations.

“It is vital that we better identify brain injury at the earliest possible stage in the criminal justice system.”