Young people with conduct disorder show a significantly reduced amygdala response to the emotions of others, according to a new MRI study published in the journal Social Cognitive and Affective Neuroscience.
Conduct disorder is an anti-social behavioral condition involving symptoms that range from lying and truancy to physical violence and weapon use in more extreme cases.
The new findings offer clues into why young people with the most severe forms of antisocial behavior struggle to control their emotions and might be more susceptible to developing anxiety or depression as a result.
For the study, researchers from the universities of Bath and Cambridge in the U.K. and the California Institute of Technology wanted to understand more about the wiring of the brain in adolescents with conduct disorder. To do this, they used neuroimaging methods to investigate the link between brain connectivity and the severity of conduct disorder and psychopathic traits (deficits in guilt, remorse and empathy).
By looking at functional MRI scans of young people with conduct disorder as well as typically-developing teens, the team was able to analyze the amygdala — a key part of the brain involved in understanding others’ emotions — and how it communicates with other parts of the brain.
Previous research by the same team suggests that adolescents with conduct disorder find it difficult to recognize angry and sad facial expressions, and so the purpose of the new study was to determine what is going wrong at the brain level.
They found that young people with conduct disorder showed significantly reduced amygdala responses to angry and sad faces. Patients with amygdala damage present a host of problems such as reading others’ emotions and, given the similarities in behavior between these patients and youths with conduct disorder, scientists had previously hypothesized that the amygdala might be damaged or dysfunctional in some way.
When the researchers analyzed connectivity between the amygdala and the brain’s prefrontal cortex — the region responsible for decision making and behavioral inhibition — they discovered surprising clues that could help explain why certain groups of young people with conduct disorder find it difficult to control their emotions.
Contrary to previous theories, young people with conduct disorder and high levels of psychopathic traits showed normal connectivity between the amygdala and the prefrontal cortex, whereas those with conduct disorder alone showed abnormal connectivity between these brain areas.
“These results may explain why young people with Conduct Disorder, but without psychopathic traits, find it difficult to control their emotions — especially strong negative emotions like anger,” said Dr. Graeme Fairchild from the department of psychology at the University of Bath.
The brain regions that are normally involved in regulating the emotional areas of the brain appear less able to do so in adolescents with conduct disorder alone. Over time, this could lead to these young people developing comorbid mental health problems such as depression or anxiety, whereas youths with psychopathic traits might be protected from developing such problems.
“This study shows that there may be important differences between youths with high and low levels of psychopathic traits in the way the brain is wired. The findings could have clinical implications, because they suggest that psychological treatments that enhance emotion regulation abilities are likely to be more effective in the youths with conduct disorder alone, than in the psychopathic subgroup,” said Fairchild.
As an under-researched and often misunderstood condition, the researchers hope these results can lead to more targeted interventions to better help young people with conduct disorder and their families. This might include neurofeedback treatments which could train young people to control activity in specific parts of their brains using MRI.
Currently, the researchers are conducting a large-scale European study to investigate any potential gender differences in young people with conduct disorder.
Source: University of Bath