Nearly 50 percent of children diagnosed with ADHD will continue to suffer from this disorder as adults, according to research published October 15. Changes in a part of the brain, the cerebral cortex, are responsible for the continuation of ADHD (Attention Deficit Hyperactivity Disorder) symptoms into adulthood, reports Philip Shaw, Ph.D., from the National Human Genome Research Institute in Maryland.
Shaw and his colleagues found that thinning of the cerebral cortex increases in children whose ADHD continues into adulthood. In comparison, children who did not exhibit ADHD symptoms in adulthood had brain structures similar to people who never had ADHD.
"Differences in patterns of brain growth are linked with differences in the adult outcome of childhood ADHD. Differences in these regions – specifically a thinner cortex – are found in childhood ADHD," Shaw stated. "For the group whose ADHD improved with age, these differences tend to resolve and by adulthood, these regions did not differ significantly from individuals who never had ADHD. By contrast, for the group with persistent ADHD, childhood differences persisted in the 'attention' regions of the brain."
Before beginning this research, Shaw and his colleagues knew several factors that were not the cause of ADHD symptoms continuing into adulthood. These factors are:
- ethnic background
- socioeconomic class
- symptom severity
The researchers also knew that thinning of the cerebral cortex was present in adults with ADHD.
The purpose of this research was to determine what causes ADHD symptoms to continue into adulthood. Shaw and his team studied 92 children with ADHD. They followed the children from about age 11 to 24-years-old. A control group of 184 people without ADHD was also included in this study. The study participants had both clinical assessments and imaging scans (neuroanatomic magnetic resonance imaging) done.
The researchers concluded that thinning of the cerebral cortex is related to the continuation of ADHD symptoms into adulthood. Shaw acknowledges that more research in this area is needed to further understand this connection. He commented "understanding how differences in brain development are tied to the course of ADHD is the first step in developing tools to help us predict the outcome of childhood ADHD."
Cerebral cortex description
The cerebral cortex is the outermost layer of the brain or cerebrum according to Healthline. The cerebral cortex consists of billions of neurons and glia. Neurons act as transmitters of information. They are cells that send signals to different parts of the body. Glia cells protect and support neurons.
“Trajectories of Cerebral Cortical Development in Childhood and Adolescence and Adult Attention-Deficit/Hyperactivity Disorder” appears in the journal Biological Psychiatry.