As new mental health disorders are christened by the mental heath community, there's been debate about whether some of these additions are really warranted, especially in kids. Some question, for example, whether disorders like ADHD are legitimate neurobiological processes, or whether they're constructs of our (adults') desire to homogenize child behavior - and label (and often medicate) the stuff that's different. But a new study shows that a more serious behavior disorder - conduct disorder (CD) - can be seen in the cells of the brain. Whether brain scans will help us understand and sort out behavior disorders more effectively is another question.
The new study, from University of Cambridge, scanned the brains of 22 young women with Conduct Disorder (CD), who were between 14 and 20 years old, and compared them to controls without CD.
Conduct Disorder is Linked to Clear Causes
Conduct disorder is marked by fairly serious behavior problems, like breaking rules for no clear reason, harming other people or animals, lying, not attending school, running away, and vandalizing property, according to the NIH. All the things that contribute to a young person having CD aren't exactly clear, but it's linked to certain factors, like child abuse, parental drug addiction, traumatic life experiences, genetic differences, and brain damage. It's more prevalent in males, though in England, where the current study was carried out, it's on the rise in girls, which makes it especially important to study in this group.
The researchers found that the girls with CD had less gray matter in an area of the brain called the amygdala, which not only governs our fear response, but it plays a role in our perception of whether others are experiencing fear or not. They also found that the insula was smaller in females with CD - this brain region is responsible for emotional processing, and in particular, feeling empathy toward others. Earlier studies have found that insula size is positively correlated with empathy: that is, the bigger the insula, the more empathy one has. And in general, all brain changes were more pronounced in kids with more significant behavior problems.
Neither Nature or Nurture is 100% Responsible
Whether the neurological changes are due to the brain biology that one is born with or due to changes that come after certain life experiences remains to be seen. Study author Andy Calder told the BBC that "The origins of these changes could be due to being born with a particular brain dysfunction or it could be due to exposure to adverse environments such as a distressing experience early in life that could have an impact on the way the brain develops." Since many behavior patterns, and disease processes, are a combination of nature and nurture, it wouldn't be totally surprising if some children are predisposed to behavior problems genetically, and life experiences then tipped the balance into a full-blown disorder.
There were also some interesting connections with ADHD. For instance, one brain region called the striatum, which is involved in motivation, reward, and cognitive control, was also reduced in females with CD. But the differences faded away when ADHD was taken out of the equation. Previous research has linked ADHD to changes in this brain region, suggesting that there is some overlap in these disorders. And, in fact, CD is well known to occur simultaneously with other disorders, like ADHD, mood disorders, post-traumatic stress disorder, and anxiety.
How the results of studies like this one will impact how and when the disorders are diagnosed isn't quite clear. As we understand more about the physical differences between the normal brain and brains with disorders, we may be able to help patients sooner and better, but that may be some years down the road.
Exploring Teens Brain Make-up to Determine Innocence or Guilt
Of course, the issue of brain changes being used as legitimate defenses in crimes - along the lines of, "my brain made me do it" - is a hot topic. Being careful to specify on which side of the pond this issue exists, Calder pointed out, "In the US, people are already using brain scans to argue diminished responsibility. I think we're too early in our understanding to really do that, but it is happening."
At least the study offers support to the idea that if there's something psychological going on in a person - like behavior or conduct problems - there's got to be something biological underlying it. Even today, some people doubt that this is the case, but hopefully studies like this will work to reduce that notion. Not that brain structure differences should be used as excuses or defenses for people's actions, but at least they will add support to the fact that in most (perhaps not all) cases, behavior problems like these are not just fluffy psychological constructs, but in fact, they're quite real, and grounded sturdily in biology.
This story was previously published by Forbes with Alice G. Walton, contributor.