Differences in brain structure between siblings make some more susceptible to developing severe anti
Differences in brain structure between siblings make some more susceptible to developing severe antisocial behavior
Conduct disorder is characterised by repetitive patterns of aggressive and antisocial behaviour. It results in substantial personal and financial costs for affected individuals, their families and society in general and is one of the most common reasons for referral to Child and Adolescent Mental Health Services in the UK.
Conduct disorder has a prevalence rate of around 5% among young people aged between 5 and 16, although there is a steep social class gradient: a 2004 survey revealed almost 40% of looked-after children, those who had been abused or on safeguarding registers, had conduct disorder. Despite all this, general awareness of the condition remains low and it is not recognised by many psychologists or psychiatrists.
The new study, published today in the journal Psychological Medicine, sought to understand underlying mechanisms which might determine someone's risk of developing the condition. The international team, including Dr Graeme Fairchild at the University of Bath, conducted MRI brain scans on 41 adolescents with conduct disorder, 24 unaffected siblings (who had a brother or sister with conduct disorder but did not show the condition themselves) and 38 typically developing controls with no family history of conduct disorder.
Their analysis found that young people with conduct disorder and their relatives both displayed structural differences in the brain -- in a part of the brain called the inferior parietal cortex. However, there were also structural changes in the brain that were specific to the conduct disorder group in brain regions responsible for empathy and cognitive control / inhibiting behaviour that were not found in the unaffected siblings.
In addition, the researchers also found changes in the prefrontal cortex, a brain area involved in planning and decision-making, that were specific to the unaffected sibling group -- which may explain why they are protected from showing antisocial behaviour despite growing up with either environmental or genetic risk factors for conduct disorder. Previous work from the same team found that despite differences in antisocial behaviour between siblings, both those with conduct disorder and their unaffected siblings had difficulties in recognising emotional facial expressions.
https://www.sciencedaily.com/releases/2021/10/211004203436.htm
