Detection of ADHD more accurately: Study

01/13/2022 4:37 PM IS

Washington [US]January 13th (ANI): A new study has identified a new neurological marker for attention deficit disorder with or without hyperactivity.
The research was published in the “Biological Psychiatry Cognitive Neuroscience and Neuroimaging Journal”.
With support from the national research center Synapsy, neuroscientists from the University of Geneva (UNIGE), the Center for Biomedical Imaging (CIBM) ​​and the University Hospital of Geneva (HUG) focused on a new electroencephalographic approach called microstates to identify neurological signatures.
The microstate technique is used to look at the combined spatial and temporal aspects of brain activity. Using this technique, the research team discovered that a certain cerebral activity state associated with sleep and alertness lasts longer in people with ADHD. The results provided evidence of a more robust ADHD biomarker, helping make psychiatry a more precise medical discipline.
ADHD affects five percent of adults, making it one of the most common mental disorders. The current clinical diagnosis is based only on questionnaires that mainly focus on the symptoms of inattentiveness and impulsiveness. However, neuroscientists speculate that while the causes of ADHD, while not yet known, have a biological and genetic basis, suggesting that there may be biomarkers that could help diagnose it.
That was the aim of this new study, supported by Synapsy, a research center that for the past twelve years has combined psychiatry and neuroscience to understand the neural basis of various mental disorders in the hope of finding better ways to diagnose and treat them to accomplish.
Studying the human brain is a difficult endeavor because we cannot directly access the brain to study its cellular and molecular mechanisms. Therefore, non-invasive examination methods such as brain scans or electroencephalograms (EEG) are used. The latter test uses a network of electrode sensors placed on the subject’s scalp to measure the electric fields generated by large neural networks.
Recent studies have shown abnormal EEG activity in patients with ADHD, suggesting that abnormal cerebral development may be the cause of ADHD.
Unfortunately, the data vary too much from study to study, making them unreliable markers for ADHD.

“These variations are either due to the great heterogeneity of the causes of ADHD or because traditional EEG analyzes are not a good tool to investigate because they do not take into account the spatio-temporal aspects of brain states,” said Tomas Ros, Researcher at the Department of Psychiatry and Neuroscience of the UNIGE Medical Faculty.
The brain activity fluctuated successively from one state to the other in the resting state and manifested different spatial configurations in the electric field of the EEG. Neuroscientists most commonly speak of five “micro” states, or major configurations, labeled A through E.
These different states remain stable for about a hundred milliseconds and change from one to the other, hence their name micro-states. An EEG can identify them and their frequency, duration, and order of occurrence can be extracted from the recordings.
Using this approach, the researchers found differences between adult patients with and without ADHD. The cerebral microstate A appeared to have a shorter duration in patients diagnosed with ADHD.
“By comparing this observation with clinical questionnaire data, we found that this condition was inversely correlated with symptoms of inattention,” said Victor Ferat, researcher at the Functional Brain Mapping Laboratory and lead author of the study.
Interestingly, the team observed that microstate D had a longer duration in patients with ADHD and this was associated with increased sleep disorder, a typical symptom of ADHD.
Just as scientific findings have to be reproduced in the field, the research team then repeated their analyzes with a separate patient cohort to check the generalizability of the results.
Through a collaboration with Prof. Martijn Arns, the head of the Brainclinics Institute in the Netherlands, the first data collection of 66 patients diagnosed with ADHD and 66 people in the control group was recorded from a separate cohort of 22 validated ADHD patients and 22 control persons at the HUG from the ADHD unit under the direction of Prof. Nader Perroud, co-author of the study.
“In this case, we replicated the results for microstate D, but not those for microstate A,” said Victor Ferat.
Microstate D thus appeared to be a replicable brain biomarker for ADHD. In addition, in this population it appeared to be associated with insomnia, a key aspect of ADHD. These findings are a valuable tool for research, diagnosis, and even treatment.
“This biomarker could be monitored in real time during brain training with neurofeedback, for example,” says Tomas Ros. (ANI)


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