When I went to a psychiatrist some years ago to see if I could be diagnosed as having ADD/ADHD, I was very surprised that he said the easiest way to test would be to first prescribe me the controlled stimulant medication – and simply see if it worked.
This happens to be a very common method for selecting medications for many ailments, especially psychological conditions. The reason for this is two-fold, first there is no 100% accurate way to diagnose ADHD due to it being a behavioural disorder with a large amount of subjectivity. Secondly, medications affect people differently and so there often needs to be experimentation with multiple medications before the ideal one is found.
This trial and error approach, while a legitimate one, is very old fashioned and inefficient. Yesterday PsychCentral publised an article stating that we are close to a stage where we will be able to test our DNA, resulting in a better understanding of our unique biology and biochemical makeup, resulting in a far more personalised efficient selection of medications that metabolise best in our bodies.