AH does he have trouble getting to sleep, staying asleep or is it that the sleep is low quality?
Ds1 has delayed sleep phase disorder (he doesn't produce enough melatonin and hasn't since he was little). I read up on it when he was diagnosed aged 10. It seems that the problems get to critical levels in the teens because the amount of melatonin produced dips anyway.
We tried him on taking synthetic melatonin (had a friend post it from the US where it can be bought in their supermarkets, unlike here where a prescription is needed). That sort of worked but looking back I think it just took the stress away.
What worked in the end was a simple eye mask and a cool bedroom, plus a regular bedtime. If Ds was allowed to stay up late even once, it would take him 2 or 3 weeks to get back into the routine of being able to go to sleep at a reasonable hour.
The whole blue screen stuff that is much talked of these days seemed to make no difference.
I think what works for one, doesn't for the next. So, its about trying everything out and finding out what works for you.
I don't think we have fully cracked it. Ds still struggles more than most with being excessively tired until about 10 am but it is manageable.
Personally, i wouldn't wait for a doctor to start making suggestions. You could try the blue screen, regular (but reasonable - not hugely early!) bedtime, darkened room and eye mask now. Either you will see a huge difference in about two weeks or none of those are the solution.