Well, there is some truth is what you say. But things have changed a lot since you were diagnosed. And, of course, it's always possible that you did have a lot of issues with you dad not being around (a lot of kids do). But, you could also have had ADHD which would greatly magnify these issues. You certainly were not treated correctly. And, unfortunately even today, some kids get the short shaft due to overworked and uniformed doctors.
However, to say that doctors are being made richer by these meds is a huge, gross generalization. First, many of these meds are generics and the profit is low, even to the drug companies. At least in California (and I suspect most states), a doctor is forbidden by law to make money off of prescribed meds. There exist clinical guidelines for the diagnosis of ADHD, (It must appear in two or more settings, meet at least 6 of 9 symptoms, etc) that should reduce misdiagnosis - but it still happens.
As for your little guy. Yes, we get questions all the time why their child is suddenly going nuts and many times it is due to the new one in the house.
If is behavior is only happening at home, then its a pretty good chance that is what is going on. Here is a link to some advice we gave a while back for non ADHD bad behavior - http://www.medhelp.org/posts/Child-Behavior/Anger--frustration-mangement-for-my-5-year-old/show/1410486
And this is a quote from one of my more recent posts that seems relevant. By the way, we always talk about finding the triggers if possible and working from there.
Any way, hope this advice also helps"
" I am sure that at school he gets told "no" and apparently doesn't throw tantrums. So, he does have the ability to control himself. Unfortunately, he has kind of "learned" that his tantrums work for him. This is not that unusual for smart kids. Fortunately, they can usually pretty quickly figure out when things are not going there way - and try something else.
And a 6 year old boy can be a force of nature. I always thought my kindergarten/first grade teachers were absolute Saints for dealing with them.
Oh, do you have any younger kids (say around 2 or 3)? Sometimes these things start as attention getting and escalate. If so, there are a few additional things you can do.
So - do realize that possibly that some of the things you want him to do maybe aren't real easy for a 6 year old. So cut back just a bit (not a lot) on the do's and don't list. Try and redirect when possible.
But mainly don't, "spend a large portion of my day saying "the way you are acting is why we aren't (insert whatever activity here)" and he doesn't seem to get that... " Talking to him just will not work. And talking to him when he is having a tantrum - won't work.
The rule is that when he starts a tantrum - he gets a short timeout. And the timeout does not start until the tantrum stops. He will go nuts for a while. Just keep repeating - "as soon as you choose to stop your tantrum, the timeout will start and 2 min later you can ..." Do not try to reason with him or talk with him while he is yelling. You are just playing into his hands.
Essentially, the rules for behavior modification are that there must be immediate, short, consistent consequences. Do not expect overnight miracles. It has taken him awhile to get to this point and it will take a while to relearn control. But he will.
I would also look into buying "Cool down and work through anger" or "When I feel angry". This is part of a series of books aimed at 4 to 7 year olds and meant to be read to them at night (several times) and then practiced. Kids do need to be taught how to deal with anger. You do not try and use these techniques while he is screaming. But once he stops or later on in the day - you can refer back to them or pull the books back out.
You can find them here - http://www.amazon.com/Cool-Through-Anger-Learning-Along/dp/1575423464/ref=pd_sim_b_5
Hope this helps - it should:) Oh, and do let me know if he has any younger siblings. Best wishes.