Thanks everyone for the comments on 7 yo. He also has no cause/effect realizations. when you ask him specifics about a bad behavior he shuts down and will stare at you and you cant get him to say anything.there is no reasoning with that. he is on adhd meds as well as antidepressant, but stil cannot seem to relax. he is always tense. have you seen this in your kiddos?
Freezing is one of the responses to fear -- we're all familiar with fight or flight, but recent research has added freeze to the options. In those instances, your son is feeling a level of stress that is outside his window of tolerance. When he freezes, rather than trying to get anything from him, realize that his brain is reacting to a perceived life or death threat (think about a deer caught in the headlights, unable to run from the approaching car) and lovingly remind him that he is safe with you and nothing bad is going to happen to him. You can deal with whatever caused the problem later, when he's feeling less stressed and his cognitive faculties are working.
When faced with significant stress his conscious mind is overruled by lower parts of his brain; his short-term memory is short circuited; anything he says or does is intended to get him out of the threatening situation and back to a mental state where he feels comfortable enough to relax, though a dysregulated child is always in a state of alertness, unable to truly relax. It's doubtful that any medication you would actually want to give to a 7 yr old would be able to cause the lower parts of his brain to relinquish their defensive survival strategy. He's a mouse living in room full of cats looking for a hole in the wall to hide in. If you can read about the Stress Model presented in "Beyond Consequences, Logic, and Control" I think you'll find a lot of answers. There's also a web site that supports the book, [url=http://www.BeyondConsequences.com]Heather T. Forbes, LCSW[/url].