Feb. 17 (UPI) -- Stealing, bullying, lying -- it turns out these antisocial behaviors may have their origins in the brain structures of individuals who engage in them, a study published Monday in the journal The Lancet Psychiatry has found.
Researchers from the United States and Britain used MRI scans to compare the brain compositions of those with a history of these behaviors to those without. In general, they found individuals who exhibit persistent antisocial behavior over the course of their lives may have thinner cerebral cortices and smaller surface area in some regions of the brain than others.
However, there were no widespread structural brain abnormalities observed in a larger group of individuals who exhibited antisocial behavior only during adolescence, the researchers said.
"Political approaches to juvenile offending often swing back and forth between punitive measures and approaches that give young offenders room to reform," co-author Terrie Moffitt, a clinical psychiatrist at Duke University Medical Center, said in a press release.
"Our findings support the need for different approaches for different offenders -- however, we caution against brain imaging being used for screening, as the understanding of brain structure differences are not robust enough to be applied on an individual level," Moffitt said. "Instead, we need to recognize that individual development can be one driver of serious repeat offending, but to also appreciate that this is not the case for all juvenile offenders."
Adolescents who exhibit persistent antisocial behavior beginning in childhood are often diagnosed with conduct disorder, Moffitt and her colleagues said. These children are at an increased risk for incarceration and poor physical and mental health later in life, they added.
Previous studies have demonstrated marked individual differences in the age of onset and duration of antisocial behavior, suggesting that some individuals display life-course-persistent antisocial behavior that begins in childhood and lasts into adulthood, while others begin engaging in antisocial behavior in adolescence and stop as they mature into adulthood. However, this is the first study to compare structural brain differences using neuro-imaging in individuals with either life-course-persistent or adolescent-only antisocial behavior and those without antisocial behavior.
As such, the authors think their findings provide the first robust evidence that underlying neuro-psychological differences are primarily associated with life-course-persistent antisocial behavior.
The researchers used MRI brain scans from 672 participants who were 45 years of age. The participants were previously categorized based on patterns of behavior they exhibited, using reports from parents, caregivers and teachers, as well as self-reports of conduct problems between 7 and 26 years of age.
In all, 12 percent of the participants had life-course-persistent antisocial behavior, while 23 percent had adolescent-only antisocial behavior. The majority -- 66 percent, or 441 -- had no history of persistent antisocial behavior.
Analyzing the brain scans, the authors measured and compared the average cortical thickness and cortical surface area -- indices of grey matter or brain tissue size -- between these three groups. They also looked at differences in the surface area and cortical thickness of 360 different regions of the cortex, most of which have been previously linked to antisocial behavior through their involvement in goal-directed behavior, regulation of emotions and motivation.
They found, on average, across the entire brain, individuals with life-course-persistent antisocial behavior had a smaller mean surface area and lower mean cortical thickness than people who showed no persistent antisocial behavior. In addition, people who showed life-course-persistent antisocial behavior had reduced surface area in 282 of 360 brain regions, and had thinner cortex in 11 of 360 regions
Widespread differences in brain structure were not found, however, for the adolescence-limited group compared with either non-antisocial or life-course-persistent antisocial groups.
The findings provide the first robust evidence to suggest that underlying neuro-psychological differences exist in people with life-course-persistent antisocial behavior, the researchers said -- and have implications for the way we treat juvenile offenders.
"Our findings support the idea that, for the small proportion of individuals with life-course-persistent antisocial behavior, there may be differences in their brain structure that make it difficult for them to develop social skills that prevent them from engaging in antisocial behavior," said co-author Christina Carlisi, a post-doctoral fellow in adolescent mental health at University College London.
"These people could benefit from more support throughout their lives," Carlisi said. "Most people who exhibit antisocial behavior primarily do so only in adolescence, likely as a result of navigating socially difficult years, and these individuals do not display structural brain differences. It is also these individuals who are generally capable of reform and go on to become valuable members of society."