The understanding of attention deficit hyperactivity disorder (ADD/ADHD) has evolved over years of research, beginning with the belief that it’s a purely behavioral issue. From further studies sprung the question of ADHD’s relationship to neurotransmitter levels in the brain. Chemical imbalances and the developmental environment were believed to work together to produce the range of ADHD symptoms. These factors put ADHD into the same mental health realm as anxiety and depressive disorders. In more recent years, though, studies show that the ADHD brain often has visible structural abnormalities. This would explain why it either gets better or worse as someone with ADHD approaches adulthood.
Imaging studies for ADHD brain abnormalities
A variety of studies have looked at the brains of children with ADD and ADHD compared to those without any indication of ADHD symptoms. These studies looked at the basal ganglia and patterns in the neurons, as well as the overall structure of major parts of the brain. Children used for the studies were typically between 8-10 years of age. Whenever possible, they were re-scanned several years later in order to map the changes as each child matured.
Differences found in ADHD brain structure
The differences found in the ADHD brain were widespread, but fairly apparent. Boys showed more differences than girls. In general, these children had narrower basal ganglia, as well as distinct changes in the cerebral cortex. Dividing tissues were thinner in areas pertaining to concentration, and the ADHD children had an overall lower brain mass. Surprisingly, many of the brain scans showed higher mass and development in memory centers in the brains of ADHD kids than in non-ADHD kids.
Implications of ADHD brain studies
While imaging studies done through 2012 can’t definitively assign brain structure rules to people with ADHD, it is a compelling area of study. With a developing understanding of which parts of the brain control which functions, it will become easier to interpret the differences that ADHD brain scans show. Because notable structural differences do seem to be present in the majority of ADHD cases, it may eventually be possible to simplify ADHD diagnosis. Instead of a huge set of behavioral elements, diagnostic testing may come down to a brain scan.
As the ADHD brain matures, some of the brain structures may also mature to a more typical mass – particularly, the tissues dividing concentration centers in the brain. These children may see improvement or cessation of their ADHD symptoms as they reach adulthood. Others, though, have structural differences that stay the same or move even further from the typical brain as they mature. These children will potentially have more obvious symptoms in adulthood, even though some may change. Adults with ADHD often have more trouble concentrating and/or a higher capacity to hyper-focus, and may have symptoms that aren’t typically seen in children, such as petit mal seizures.
The brain is extremely complex, and the medical community may be years away from diagnosing ADHD with brain scans, but these studies indicate that it is possible. For one of the most over-diagnosed conditions in the United States, this is good news for the people who need accurate diagnosis and support for their ADHD.