Kamtwins, it sounds like your son has rebound problems with the Concerta. It happens. If he's doing well otherwise, that seems to back up the diagnosis and is a good sign.
There are other stims - our kids are on dex which we get privately compounded into a sustained-release form. easy child 2/difficult child 2 has only ever been on dex, but difficult child 1 used to be on ritalin (Concerta is slow-release ritalin). He was good at first but as he grew and the dose increased, we found he had bad rebound. Because we didn't have Concerta in Australia in those days, we were seeing rebound several times during the day, with the added problems that he wouldn't remember to go take more medications when they were due (and our idiotic system here wouldn't remind him!).
When difficult child 3 & easy child 2/difficult child 2 were diagnosed they were immediately started on dex, which to begin with was administered in the standard (short-acting) form.
In December last year we tried difficult child 3 on Concerta - we figured it would be cheaper. But we found he had rebound problems - in him, he was very talkative, almost pressured speech and couldn't be shut up. It was as if all the hyperactivity of the day was being concentrated into this evening behaviour. We also found that the dosage was too low for him, which told us that if we increased the dose to the correct level we'd have even more rebound.
difficult child 1's rebound - he would get angry, aggressive and at times violent. easy child was talking about it when she rang the other night, she remembers difficult child 1 trying to stab her with a soldering iron (mercifully, not switched on).
Rebound can affect different kids in different ways. Not all kids get rebound and no one stimulant is exclusively responsible. A good friend of mine had her son on stims - he reacted with rebound to dex, but not on ritalin or Concerta.
Other medications can give quite different reactions to different kids - your twins are just as likely to have different reactions as any of my kids.
Rebound is part of the problem. but it alone isn't what you are having trouble with now - I believe your problem with him is that his usual behaviour has been aggravated by rebound, not that it has caused these major changes.
What you described is something we've had to deal with often - difficulty task-changing. Rebound has probably only made it more apparent and reduced his ability to adapt and cope.
Task-changing problems are interesting - they generally are much worse when they're enjoying what they're doing but they can even be an issue if the task the child is doing is an unpopular one (such as homework). To work on this you need behavioural techniques - with a lot of problems our kids can have, medications only ease things a bit, medications can't cure anything or even make symptoms disappear entirely.
ADHD kids - hey, difficult children in general - tend to be worse in the evenings anyway. They've been working hard concentrating, trying to hold themselves together during what can be difficult days especially at school. They come home and relax, which can then trigger some bad behaviour. It happens at home because they feel safe, they feel loved and they let their guard down a bit too far.
A book that can help a lot if "The Explosive Child" by Ross Greene. There is some good discussion on this in Early Childhood forum.
difficult child 3 had/has big problems changing tasks. An example is the best way to show you what we do.
difficult child 3 is playing a computer game. It's evening. There are chores to be done, a shower to have, dinner to eat. These other things don't always happen in ordered sequence and difficult child 3 is drawn back to his computer game. Ini the past we had to ban all computer games after 5 pm, but if he was sitting around moping and had a break between various tasks, he would get annoyed that he couldn't use those down times to play a bit more. In our case, we chose to allow the games on condition he would stop them to do what had to be done.
That's one way. But if you've ever played a computer game, you will know that sometimes especially if the game is fast-paced and intense, there isn't an option to pause or quit. And by this stage the player has become involved in the game to the point where they just can't instantly shut off their interest.
What we used to do - we'd ask for instant compliance. Not good, because you generally either don't get it, or you get it with a grumble.
What we do now - we give warnings. "difficult child 3, I need you to go run the bath. It will take you about ten minutes, I need it done as soon as possible, preferably within fifteen minutes. Get yourself to a save point, or pause."
When we first began to do this, we had problems because difficult child 3 would forget he'd been told. So we put a sticky note near the computer screen with the required task and the time he'd been told. That way if he tried to say, "You didn't tell me!" we could point to the note. (And seriously - when you ask a kid to do something and he's busy concentrating on his computer game, he is QUITE capable of answering you and not remembering it later).
We modify it a bit - "Son, I need you to go have your bath. It's at just the right temperature for you now. How long before you can leave that game?"
difficult child 3 himself knows the commonsense in this - if he says, "I've just begun a new level, it will take me about half an hour to do it," then it makes sense to say, "If you wait half an hour you will have a cold bath. How do you want to do this? You could just drop the level, you've only just started it so that would be no big deal - or could you pause it and come back to it after your bath? Keeping on playing is not a good idea, if you want a warm bath."
If he fails to comply, his punishment is a cold bath. YOU didn't make it cold.
Whatever tasks you need him to change to, you need to give him time to adapt. You will get better compliance from him, if he feels secure in what you will do to get compliance. If he is playing his game and is afraid at any level that you will simply shut off his game, he will be very anxious about it. That anxiety gets expressed as anger, as hostility, as aggression and what is perceived as rudeness in the extreme. If you actually DO shut off the game, you will trigger a meltdown.
"Explosive Child" helped me understand that the only way some kids (like difficult child 3) can really learn to show respect, is if we teach by our example in how we treat them. I should have realised this sooner, of course. Back when easy child 2/difficult child 2 as a toddler said to me, "Why did you just pour me milk? I asked for juice and you poured me milk! How many times do I have to tell you? I DON'T LIKE MILK!"
Shutting of a child's computer game is the same as that child shutting off your computer mid-post, or grabbing the newspaper from you while you are in the middle of writing down a crossword answer. Mid-word.
Most parenting these days works by asserting parental authority along the lines of "Because I said so." This works for most kids. However, it works LEAST with difficult children, especially those with a heightened sense of justice. This alternative method - it works. And it doesn't turn you into a doormat either. It actually seems to fast-track the child learning to be self-reliant and taking personal responsibility. Natural consequences, again.
Read the book. Before you get it, read the discussion on the book. Call the psychiatrist by all means - I think you're making a good call there. You shouldn't live with bad rebound if you can find an alternative.
Welcome to the site, I'm glad we're here for you. Sorry you need us, but there is loads of help here. Many of us have been where you are now, and have come through it.
Marg