STATES CHRONICLE – Scientists have finally revealed substantial evidence that indicates attention-deficit/hyperactivity disorder (ADHD) is a neurological disorder. They concluded that this common illness should be considered an issue of the brain caused by delayed maturation. Moreover, no evidence supports the idea that this could be a problem of parenting or motivation.
People who have ADHD have different brain structures compared to non-ADHD people. An international team of scientists has developed one of the greatest studies of brain imaging. They have unveiled that this neurological disorder involves a reduced volume in significant brain areas, mainly the amygdala, being responsible for governing emotions.
The newly developed study was published on February 15 in the Lancet Psychiatry magazine. It included data on adults, adolescents, and kids living with ADHD. Nevertheless, the most prominent differences in brain volume were revealed in children. The study proved that five out seven subcortical brain areas were smaller in people with ADHD compared to people from a control group.
The regions which had a reduced volume were the amygdala, the hippocampus, the nucleus accumbens, the putamen and the caudate nucleus. The hippocampus constitutes the area where our memories form, while the nucleus accumbens is the area responsible for processing motivation and reward. The putamen is the brain region involved in delivering stimuli responses, also focusing on learning. The caudate nucleus was linked to purpose-directed actions.
Martine Hoogman, a geneticist at Radboud University in the Netherlands and also the first author of the study, claimed that the amygdala is a brain structure which was not known to be involved in the evolution of ADHD. Researchers knew that this brain area is involved in recognizing emotional stimuli and regulating emotions. Nevertheless, other studies in the past have shown that it is also involved in the process of repressing a response.
Hoogman stated that both processes are known to be key factors in the development of this neurological disorder. The group of scientists which conducted the study participate in a worldwide consortium called Enhancing Neuro Imaging Genetics through Meta-Analysis (ENIGMA).
Their primary purpose is to bring together as many specialists as possible in fields, like psychiatry, neurology, genomics and imaging to develop a better understanding of brain structures. The new study was developed at 23 different location in nine countries, being built by a team of 80 researchers.
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