While much is still unknown about the ties linking traumatic brain injuries (TBI) and criminal activity, a growing body of evidence suggests a history of brain injuries is associated with a significantly increased risk of committing criminal offenses.
A new Australian study published in PLoS ONE suggests experiencing a TBI could potentially increase the chance of an individual participating in criminal activity by as much as 60 percent.
The study, involving researchers from the University of Western Australia and interstate universities, used records collected from approximately 30,000 Wester Australians born between 1980 and 1985, including approximately 8,000 with hospital records indicating a past brain injury.
To properly assess the impact of brain injury on criminal behavior, Dr. Peter Schofield, clinical director of Neuropsychiatry Service at Hunter New England Local Health District, said it was important the team gather evidence about other ‘confounding’ factors.
“Substance misuse, some psychiatric conditions, and social disadvantage increase the risk both of having a TBI and of committing offences,” he says.
“Taking into account these and other factors allowed us to tease out the specific, separate role TBI might have in terms of increasing the risk of offending.”
The study also used a control group consisting of siblings of participating individuals with TBI, including some twins who had not experienced a brain injury.
“The main results suggest that experiencing a TBI increases the likelihood that an individual may subsequently offend,” Dr Schofield says.
“About 10 per cent of those without a TBI and 18 per cent of those with a TBI subsequently offended up to age 30 years.
These findings indicate an approximate 60 percent increase in risk related to traumatic brain injury after accounting for other factors known to independently increase the risk of first offending, such as a record of drug or alcohol treatment, a mental illness diagnosis, and evidence of social disadvantage.
The researchers say increased efforts to reduce substance abuse as well as accidents and assaults in the context of substance abuse are important steps to reduce the rates of TBI. They also encourage appropriate use of helmets in high velocity sports and when riding bicycles.
“It seems likely that improved treatment of psychiatric illness might also reduce rates of TBI,” he says.
“We think it’s likely that some individuals who enter the criminal justice system still suffer from the effects of a recent TBI and might benefit from specific treatment for that.
“Additionally, other offenders may have longer term side effects of a head injury with consequences for their behaviour and for coping with the stresses that imprisonment imposes.”