As mentioned on Medical and Other Information, having a DNA test done, whether you are looking for genetic influences or illnesses, it can also be used for targeted treatments.
There are several companies, in South Africa, what can provide you with such a service – Dnalysis. (There are others but my son’s doctor used DNAlysis).
This is what information you can get from the testing: (the pictures are of my DNA that was tested)
Here is one showing how my body will respond to any Methylphenidate medication – the base ingredient for Ritalin, Contramyl, Concetra and the like:
These test is unfortunately not cheap, but it is it is worth knowing how your body might respond to medications instead of struggling to find the one that works with minimum side effects.