̽��ֱ�� of Cambridge - conduct disorder

‘Map’ of teenage brain provides strong evidence of link between serious antisocial behaviour and brain development

cjb250 — Wed, 15 Jun 2016 23:01:00 +0000

In a study published today in the Journal of Child Psychology and Psychiatry, researchers used magnetic resonance imaging (MRI) methods to look at the brain structure of male adolescents and young adults who had been diagnosed with conduct disorder – persistent behavioural problems including aggressive and destructive behaviour, lying and stealing, and for older children, weapon use or staying out all night.

In particular, the researchers looked at the coordinated development of different brain regions by studying whether they were similar or different in terms of thickness. Regions that develop at similar rates would be expected to show similar patterns of cortical thickness, for example.

“There’s evidence already of differences in the brains of individuals with serious behavioural problems, but this is often simplistic and only focused on regions such as the amygdala, which we know is important for emotional behaviour,” explains Dr Luca Passamonti from the Department of Clinical Neurosciences at the ̽��ֱ�� of Cambridge. “But conduct disorder is a complex behavioural disorder, so likewise we would expect the changes to be more complex in nature and to potentially involve other brain regions.”

In a study funded by the Wellcome Trust and the Medical Research Council, researchers at the ̽��ֱ�� of Cambridge recruited 58 male adolescents and young adults with conduct disorder and 25 typically-developing controls, all aged between 16 and 21 years. ̽��ֱ��researchers divided the individuals with conduct disorder according to whether they displayed childhood-onset conduct disorder or adolescent-onset conduct disorder.

̽��ֱ��team found that youths with childhood-onset conduct disorder (sometimes termed ‘early-starters’) showed a strikingly higher number of significant correlations in thickness between regions relative to the controls. They believe this may reflect disruptions in the normal pattern of brain development in childhood or adolescence.

On the other hand, youths with adolescent-onset conduct disorder (‘late starters’) displayed fewer such correlations than the healthy individuals. ̽��ֱ��researchers believe this may reflect specific disruptions in the development of the brain during adolescence, for example to the ‘pruning’ of nerve cells or the connections (synapses) between them.

As the findings were particularly striking, the researchers sought to replicate their findings in an independent sample of 37 individuals with conduct disorder and 32 healthy controls, all male and aged 13-18 years, recruited at the ̽��ֱ�� of Southampton; they were able to confirm their findings, adding to the robustness of the study.

“ ̽��ֱ��differences that we see between healthy teenagers and those with both forms of conduct disorders show that most of the brain is involved, but particularly the frontal and temporal regions of the brain,” says Dr Graeme Fairchild, who is an Associate Professor in the Department of Psychology at the ̽��ֱ�� of Southampton. “This provides extremely compelling evidence that conduct disorder is a real psychiatric disorder and not, as some experts maintain, just an exaggerated form of teenage rebellion.

“These findings also show that there are important differences in the brain between those who develop problems early in childhood compared with those who only show behavioural problems in their teenage years. More research is now needed to investigate how to use these results to help these young people clinically and to examine the factors leading to this abnormal pattern of brain development, such as exposure to early adversity.”

“There’s never been any doubt that conditions such as Alzheimer’s disease are diseases of the brain because imaging allows us to see clearly how it eats away at the brain,” adds Professor Nicola Toschi from the ̽��ֱ�� “Tor Vergata” of Rome, “but until now we haven’t been able to see the clear – and widespread – structural differences in the brains of youths with conduct disorder.”

Although the findings point to the importance of the brain in explaining the development of conduct disorder, it is not clear how the structural differences arise and whether, for example, it is a mixture of an individual’s genetic make-up and the environment in which they are raised that causes the changes. However, the researchers say their findings may make it possible to monitor objectively the effectiveness of interventions.

“Now that we have a way of imaging the whole brain and providing a ‘map’ of conduct disorder, we may in future be able to see whether the changes we have observed in this study are reversible if early interventions or psychological therapies are provided,” says Professor Ian Goodyer from the Department of Psychiatry at the ̽��ֱ�� of Cambridge.

Reference
Fairchild, G et al. Mapping the structural organization of the brain in conduct disorder: replication of findings in two independent samples. Journal of Child Psychology and Psychiatry; 16 June 2016 DOI: 10.1111/jcpp.12581

̽��ֱ��brains of teenagers with serious antisocial behaviour problems differ significantly in structure to those of their peers, providing the clearest evidence to date that their behaviour stems from changes in brain development in early life, according to new research led by the ̽��ֱ�� of Cambridge and the ̽��ֱ�� of Southampton, in collaboration with the ̽��ֱ�� of Rome “Tor Vergata” in Italy.

Conduct disorder is a complex behavioural disorder, so we would expect the changes to be more complex in nature and to potentially involve other brain regions.

Luca Passamonti

Nicola Toschi

̽��ֱ��orbitofrontal cortex (blue) and medial temporal cortex (red) were more similar in terms of thickness in youths with Conduct Disorder than in typically-developing youths, suggesting that the normal pattern of brain development is disrupted.

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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Scans reveal differences in brain structure of antisocial teens

gm349 — Fri, 01 Apr 2011 09:45:17 +0000

Brain scans of aggressive and antisocial teenage boys with conduct disorder (CD) have revealed differences in the structure of the developing brain that could link to their behaviour problems.

̽��ֱ��study, by neuroscientists at the ̽��ֱ�� of Cambridge and the MRC Cognition and Brain Sciences Unit, reveals that the brain differences were present regardless of the age of onset of the disorder, challenging the view that adolescence-onset CD is merely a consequence of imitating badly behaved peers. ̽��ֱ��new research was funded jointly by the Wellcome Trust and the Medical Research Council.

CD is a psychiatric condition characterised by increased aggressive and antisocial behaviour. It can develop in childhood or in adolescence and affects around five out of every 100 teenagers in the UK. Those affected are at greater risk of developing further mental and physical health problems in adulthood.

̽��ֱ��neuroscientists used magnetic resonance imaging to measure the size of particular regions in the brains of 65 teenage boys with CD compared with 27 teenage boys who did not display symptoms of behavioural disorder.

Their findings revealed that the amygdala and insula – regions of the brain that contribute to emotion perception, empathy and recognising when other people are in distress – were strikingly smaller in teenagers with antisocial behaviour. ̽��ֱ��changes were present in childhood-onset CD and in adolescence-onset CD, and the greater the severity of the behaviour problems, the greater the reduction in the volume of the insula.

Smaller volume of structures in the brain involved in emotional behaviour has been linked to childhood-onset CD, in which behavioural problems manifest early in life. However, adolescence-onset CD was previously thought to be caused solely by the imitation of badly behaved peers. ̽��ֱ��current findings cast doubt on this view and suggest a potential neurological basis for these serious and challenging conditions, whether they emerge in childhood or adolescence.

Ian Goodyer, Professor of Child and Adolescent Psychiatry at the ̽��ֱ�� of Cambridge, and Dr Graeme Fairchild, now based at the ̽��ֱ�� of Southampton, led the research. Dr Fairchild explained: “Changes in grey matter volume in these areas of the brain could explain why teenagers with conduct disorder have difficulties in recognising emotions in others. Further studies are now needed to investigate whether these changes in brain structure are a cause or a consequence of the disorder."

Professor Goodyer added: "We hope that our results will contribute to existing psychosocial strategies for detecting children at high risk for developing antisocial behaviour.”

Dr Andy Calder from the MRC Cognition and Brain Sciences Unit, who co-led the research, commented: “Studies such as this are tremendously important in understanding the causes of conduct disorder. Only when we are confident that we understand why the disorder develops can we apply this knowledge to the further development and evaluation of treatments. ̽��ֱ��disorder has a devastating impact on families and communities, and at the moment, we have few effective treatments.”

̽��ֱ��group have previously shown that individuals with both forms of conduct disorder display abnormal patterns of brain activity, but this new work marks an important advance in understanding the biology of aggression and violence by showing that differences in brain structure are linked to the disorder.

̽��ֱ��study will appear online today in the American Journal of Psychiatry.

Brain scans of teenage boys with severe antisocial behaviour have revealed differences in the structure of the developing brain.

We hope that our results will contribute to existing psychosocial strategies for detecting children at high risk for developing antisocial behaviour.

Ian Goodyer, Professor of Child and Adolescent Psychiatry at the ̽��ֱ�� of Cambridge

g.fairchild@all, 2011

MRI brain scan highlights the insula, one of the areas of the brain that is reduced in volume in subjects with Conduct Disorder.

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