The brains of young people with the most severe forms of antisocial behaviour are "wired differently" to others - providing clues as to why they struggle to control and regulate their emotions, researchers say.

In a study, published today, neuroimaging methods were used to examine young people with the condition conduct disorder - which has symptoms ranging from lying and truancy to physical violence and weapon use.

Researchers from the universities of Bath, Cambridge and the California Institute of Technology set out to understand more about the wiring of the brain in adolescents with conduct disorder.

They used functional MRI scans of young people with conduct disorder, as well as typically-developing teens, to analyse the amygdala - a key part of the brain involved in understanding the emotions of others - and how it communicates with other parts of the brain.

Previous studies suggested that adolescents with the condition struggle to recognise angry and sad facial expressions and the latest research found they had significantly lower amygdala responses to them.

They found those with conduct disorder showed abnormal connectivity between the amygdala and the brain's prefrontal cortex - the region responsible for decision making and behavioural inhibition.

Contrary to previous thinking, youths with conduct disorder and high levels of psychopathic traits - the term used to define deficits in guilt, remorse and empathy - showed normal connectivity between these areas.

Researchers say this finding could help explain why young people with the condition struggle to control and regulate their emotions, which may make them more susceptible to developing anxiety or depression.

Dr Graeme Fairchild, from the University of Bath's department of psychology, said: "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.

"The parts of the brain that are normally involved in regulating the emotional parts of the brain appear less able to do so in the youths with conduct disorder alone.

"Over time, this could lead to them developing co-morbid mental health problems like 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."

Patients with amygdala damage show a range of problems including reading the emotions of others.

Given the similarities in behaviour between these patients, and those with conduct disorder, scientists previously hypothesised that the amygdala may be damaged or dysfunctional.

The team hope their findings can be used to create more targeted interventions to help young people with conduct disorder and their families.

They are currently running a large-scale European study to investigate sex differences in antisocial behaviour, to examine whether boys and girls with the condition show similar or different brain abnormalities compared to their typically-developing peers.

The latest study, published in journal Social Cognitive and Affective Neuroscience, was funded by The Wellcome Trust and the Medical Research Council.