I want to try and give you a word of encouragement.
Both my kids were frequent run aways.
I know the fear - the overwhelming anxiety involved with a run away situation. And yes, its true there are real reasons for anxiety. However - these kids are usually fine.
Like your son, my daughter has some emotional issues. I had many of the same concerns you have with your son. When my girl took off - she really took off. She once left school and took off with the rainbow people (a cross between gypsies and hippies) and lived for a couple months in the national forest in Illinois - I think it was.
Another time, she actually ran off with the circus.
Turned up in Mississippi.
Another time, she left for a "job" painting murals in New York, and instead ended up in Arizona. Lived for awhile in a abandoned buss.
All of these episodes where heart stopping for me. I have spent entire months crying - just not able to stop.
But she is fine. Never came to any real harm at all. Once she got to a point where no one was chasing her to bring her home - she quite running off.
My son was a little different. He never left the neighborhood. I knew exactly were he was. But the people there lied to me and the cops were useless.
It made me angry, but I wasn't as worried. Not that there weren't reasons for worry - there were - but it helped knowing, more or less, were he was.
Nothing made much difference with my daughter.
With my son, there were some things that might have helped.
I got good results on one occasion, by making a wanted poster - I took his school picture and scanned it and printed out a bunch of "posters" - If seen, call JCPD - listed the case number the cops gave me, and the cops phone number. I put them up in all his hang outs spots. The pizza hutt, the KFC, and so on. He was home before I was. Ran home in the pouring rain, just as soon as the first one was posted. The "network" gave him a heads up, I guess.
Another time, at the holidays, I used a present he wanted badly to manipulate him. Told the girl whose house he was at, if he didn't get his ass home, it was going back to the store. On that occasion, I had it set up with YMCA's shelter house for him to go there. And That might be an option to consider. They really do have a good sort of situation set up. They provide food and shelter free of charge to the kid; but the kid has to attend school or take GED classes - and they have to attend counseling with therapist provided by the Y - also free of charge. If its an older kid who doesn't want to return home, they work on independent living skills. If a younger teen, or one who wants to go home, they work on helping the family figure out ways to get along - family counseling.
If this sounds like something that might help, just call your local YMCA and ask about their shelter house program. If they are in your area - your son can access them by going into any designated "safe place" and calling them. They will go get him. This can help if you have a kid who will not go near the parents.
If you decide you really need to look into an RTC, then look at ISAC's site, and read over their warning signs - so you'll have a better idea how to evaluate the various choices.
http://www.ISACcorp.org