This is a situation we all fear as parents.  I do not have a medical backgroud but this is my take on what is starting to happen here.  One of the most important roles of HC is glucose metabolism and in his case he will probably have less energy than normal.  He will probably be hypoglycemic more often which will led to more irrational behaviour and he will be more short tempered.  I am not 100% sure but I remember something about bone density lose and any extra growth possible in his late teens will probably stop. 

I cannot believe that your endo or medical contact just told you that his skin darkening is a bad sign.  This certainly means that he is in bad shape and basically on borrowed time regarding sudden illness or a tramatic injury.  I do not know what period of time it takes for your bones to start to weaken but it will happen and the threat to injury will increase.  The stark reality is that he has no useful HC backup in his body.  Any accident without you being present will see his body go into shock very quickly.   Before my son was dx he went into shock and ICU because his systems shut down.  As we all know once fluid and sugar levels are normal our kids recovery is nothing short of miraculous and he was release after 24 hrs because nothing was found with all the tests done.  He was back in ICU 8 hrs later with no trauma. 

The bottom line here is that by not taking his medication he is committing suicide.  The fact that he may take some from time to time is like someone doing a bad job cutting their wrists.  As L. and Aimee  show  not taking meds is not uncommon  but as we also know from the board the outcomes can be worse.  L.'s advise on visiting terminally ill kids will show him how people chose life through incredible emotional and physical pressure.  My son spent 3 months in a childrens hospital because he has other medical complications on top of CAH but the kids in the cancer ward next door were amazing but many did not make it. Aimee also made the vital point that she had to chose life.  We as parents cannot do that for them but it is unfair and wrong for you to be left in a position of "what if",  which brings me onto what I would do personally in your situation if Aimee's and L's good advise from experience does not work.

This may sound extreme but I would look into it with my endo.  The fact that he has not been taking his medication may you could argue mean that he cannot act rationally in his own interest and is certainly a danger to himself.  If he is a danger to himself then he could be a danger to other people as Aimee has pointed out and they could be his friends.  You could try to point out that it is one thing chosing to die but totally different if you unintentionally  involve friends and family.  If his friends know he is not taking his meds they will feel responsible if something happened to him.  He may feel this is just about him but it will not end up that way.  You could probably legally committ him into a hospital to get his system back to normal.  This will not take long but the point here is that you will know he can make his own rational choice about chosing life as Aimee said he will need to take.  This is a nightmare for you all but at some point talking stops and action needs to be taken..  Maybe Aimee or L. can repost or e-mail you on how bad their condition got before going back to thier medication.  However, as L. points out everyone's medical case is different and being a salt waster or not will make a difference.  If his skin is darkening he is getting to an Addisonian state so if he wants more adult input from people suffering from adrenal insufficiency this is the best support group on the net: http://www.healinglight.com/cgi-bin/addisons.pl  You/he will get a more learned response than mine from more adults like Aimee and L. regarding action to take. I hope a resolution is found quickly for you all.

ShaunP.