The Damage of Cry it out and Controlled Crying

My interpretation of when people ask "what is the damage of cry it out?" is that they are wanting a scientific one stop answer which is what we would get if we were dealing with something like gravity that is a yes or no answer.
If I drop this apple will it will fall to the ground? Yes.

When we really can not get that single answer when dealing with humans - variation, anomalies and just being plain different .
What we are looking at is statistics, history and common out comes.
Many articles I've been reading are authored by people who feel that there is no damage done to babies by using the cry it out/extinction method.
But I believe they are not looking at the adult product.
By that I mean - How does an adult that has had the extinction or cry it out method used on them in their baby hood function as an adult.
These authors I feel are short sited possibly because the outcome is what we (the authors and the general population) want to see. The extinction method does seem to work (for some) which is probably why it was so heavily used (pushed by originations like Plunket and even shortsighted doctors) in the 30's 40's 50's and 60's.
But this it where science and behavioral science is starting to come in now (well it was back then too but the net was not around then to share its information) and also statistics, research into the human brain as well as the many health issues we (mostly) western peoples seem to be suffering from…obesity, depression, anxiety, panic, fear, anger, frustration, self worth, communication problems…these issues are growing causing more problems for not just the adult but many others around this adult.

Look at a few short bits from
Jan Hunt Naomi Aldort (just because we've forced them to sleep does not mean they have really learnt to sleep well)
Something I've learnt from Jan Naomi and Pam Leo is if you fill a child's need now they will not have that burning need for life. Like that friend of yours that is looking for a life partner but can never find the right one - its all part of it.
But that is looking at the Adult and the dysfunctional problems that they have…what about the child?

"...As the unconnected child gets older, much of his time is spent in misbehavior, and he is on the receiving end of constant reprimands; or he tunes out and seems to live in his own separate world. This child becomes known as sullen, a brat, a whiner, or a spoiled kid. These undesirable behaviors are really coping strategies the child uses in search of a connection. The unconnected child doesn't know how to regain a sense of well-being because he has no yardstick to measure attachment. He has difficulty finding a connection because he isn't sure what he lost…" for the full article see this link

Miss behavior is often thought by many as just a part of childhood or the parents say they have got a problem child…there are many more issues to be named in here.
While I do believe that there are some kids who are genuinely hyped up or have a little silver streak in them I do not believe that the numbers we are seeing today are all due to genetics and misfiring body chemicals.

Please see my post on Emotional Disturbance to explain my ideas in this area.
So while there may not be a firm yes or a firm no in the question does cry it out/extinction or controlled crying do damage to your child there are MANY MANY well educated people and organizations who have been finding links to the way we treat children will be the way they perform for us as parents and the way they perform with others for the rest of their life as adults.

Also see this post on the Hippocampus