As the teacher speaks in front of the class, the majority of the students are attentive and taking notes. But there is one student in the classroom looking out the window daydreaming about being outside and able to run around, free, not trapped in his chair. He has attention deficit/hyperactive disorder (ADHD). More and more students are being diagnosed with this disorder. Why? Does it have to do with our genes, the environment? Is this just a reflection on our society always needing an answer and diagnosis for why we are different or is it the doctors wanting more money?
Currently the only way to diagnose this disorder is through a series of physiological tests and accounts from your teachers and parents. These methods are very subjective and may be leading to over diagnosis of children and overmedicating (2). These students may just need to learn discipline and learn how to motivate themselves to sit in a classroom and listen to a lecture or study for an exam. Just like many other psychological disorders the most logical answer to this is to study the differences between the brain structures of those with ADHD and those without.
In a recent study (1), the researchers were after the answer to see if there is a significant difference in the adolescent brain with ADHD with and without medication and without ADHD. The researchers wanted to determine if using an MRI of a child's brain would lead to better diagnosis of ADHD. The researchers studied the participants for ten years and took a total of four MRI's for each child. The researchers concluded that there is a significant difference in brain volume and specifically the white matter and the caudate nucleus. These two differences were seen to be developed at a young age due to genetics or environment and the growth of the brain paralleled the control participants. This means that as a child you have ADHD and do not generally develop it later in life.
According to the results even though there are differences in the anatomical brain structure, this still is not a clear answer to whether or not an MRI will be able to diagnose anyone with ADHD any time soon. The limitations to the study are the participants themselves. They are unable to keep still for the MRI and many of the images had to be thrown out because of movement. Also the lack of twin and sibling studies in the topic cause us to not be able to determine how much of the differences are die to environmental or genetic influences or if it is merely a correlation.
Similarly to other imaging discussions about the validity of the images and what they tell us we are unable to definitively say. At this point much more research needs to be done on the topic of ADHD and how brain imaging can enhance one's ability to be diagnosed with ADHD and allow the subjective tests to be replaced by a more concrete method of diagnosis.