It has been assumed that the developmental disorders in some children are something that they are born with and cannot be changed. The case in point is autism. Though there are many companies working on it there has been not much therapeutic progress.
Dr Aditi Shankardass has been pioneering the use of a common EEG to help the diagnosis of those disorder. She compares the diagnosis of those disorders to those of the heart. How would it be if doctors were to diagnose us based on just our behavior when we have an heart issue. Fortunately, doctors use various parameters like blood pressure, habits, cholesterol, Electro cardiogram or even invasive imaging and catheterization to visualize the problems. In some of the developmental disorders, the children are just diagnosed based upon their behavior.
An important case is that of a small boy that was diagnosed with a developmental disorders and could not related to people or learn. Upon doing an EEG they found that he was undergoing minor epileptic attacks which had distorted his behavior. However, upon treatment with anti-epileptic medication, full and normal activity of the child was restored.
There has been previous evidence that EEG activity can diagnose autism spectrum disorders by artificial intelligence based analysis of the EEG between normal and to-be-diagnosed-Autistic babies.
In ADHD (attention deficit hyperactivity disorder), the evidence for the use of EEG is more developed but not error-free. The standard behavior test for diagnosis of ADHD is the continuous performance tests that measure the capability to hold attention on a computerized test. However, this is fraught with problems – the key among them is that there are several false negative and false positives which to a non-scientist means that the tests do not work. A method called Quantitative EEG is more useful. It has been found that in general, ADHD patients have greater proportion of (high frequency) theta waves as compared to beta waves (low frequency). This method is very useful but is not very successful to distinguish between ADHD and other psychiatric disorders
In schizophrenia, the p300 marker of EEG has been shown to be effective to some degree however, these studies are complicated by the observation that it is very difficult to compare between patients since there is significant inter-patient variability.
Even though EEG is not a perfect marker, its long history and its solid electronics based consistent measurement makes this a useful marker for many psychiatric disorders.