Those 1983 studies you are discussing are amongst the ones that were reviewed in the meta-analysis and by the Justice Department and found to have methodological flaws that made them impossible to draw conclusions from. Generally, they lost too many people to follow up.
Just because someone thinks a study is OK to put in a discussion section doesn't mean that it is actually methodologically sound.
The consensus amongst those who have looked at this area objectively-- not people who make their business selling it or people who have an emotional attachment to the idea of it-- is that there is little evidence that wilderness programs help. The evidence that does favor the approach only favors voluntary programs which take a kind, gentle, supportive approach-- not those which use force or accept kids who do not want to be there.
And in the current lax regulatory environment, it is impossible for parents to know that that is what their kids will actually get.
People who believe in this business should be supporting strict regulation-- otherwise, they have no credibility. Those who say it's OK as it is but there are a few bad apples and you can find good programs if you know how to look don't recognize that high turnover and lack of regulation means that even good programs will often have bad employees who can be seriously dangerous to kids.
Unchecked power is corrosive and leads inevitably to abuse-- these programs do not have the kinds of checks and balances to protect kids in them. If you look at military boot camps or prisons or psychiatric institutions, they are filled with attempts to check power and keep the use of force on a tight rein. Even there, there are regularly abuses and problems because the situation of having people with absolute power over others will always produce abuses, the only thing you can do is try to minimize them. This is why you want to use the least restrictive setting for kids-- to avoid exposing them to inherently dangerous institutions.
With kids, there is an extra problem: pedophiles. Any place that has lots of children will attract pedophiles-- if you don't do background checks, require little education and hire kids who were previously troubled themselves as "role models," your program is going to be a magnet for them.
So, by sending your kids to these places as they stand now, you are not necessarily making them safer than they are on the street. Sure, drug scenes attract problem people too-- but at least there, the pedophiles can rarely prevent those who want to talk to their parents from doing so and at least there, the child will be believed if he complains of abuse-- not dismissed as "manipulative."
The troubled teen business has yet to recognize these risks-- and this is why it remains dangerous, even though there may well be some kids who could benefit from some things, like communion with nature or challenge in nature.
It's also why Outward Bound for *regular* kids-- not the program aimed at those in trouble-- is at least somewhat safer. When you have ordinary kids who choose to go, they are going to be believed when they complain-- whether its about abuse or illness.
Also, it is impossible to prove a negative-- you can only say that there's no evidence that is is effective. It's like if you say all swans are white-- you can't prove it. One black swan may exist somewhere.