Lifestyle choices also have real effects on these chemicals you mention. Health experts today are like the proverbial carpenter who sees every problem as a nail to be hammered.... ex: there is no good reason to medicate a child for being hyper-active.
To say there is no reason to medicate a child for hyperactivity is huge over generalization. As a teacher I've seen kids before and after medication. Some it turns into zombies, some it allows them the function, which is what they wanted all along, but were unable to. It has helped those kids greatly to be able to take medication.
