CBT is a very effective treatment for many disorders in children esp. as their brains have much capacity still for plasticity. Used to treat PTSD in abused/neglected children and new studies show it is very effective in treating anxiety/depression in adolescents in place of meds.

Turns out our brains are stubborn; hanging on to the ole Neurons and connections, These connections are well worn, well traveled with little resistance.

I read an article lately that asked the question: why is learning so hard, and it goes into an explanation of these ole connections getting in the way of newer connections whether these new connections are additions or replacements.
The Author describe his problem of playing Squash after playing tennis most of his life...his brain and his movements always returned to the tennis moves instead of the new squash moves of the the racket.

So yes, it takes a long time to replace/change the hard wiring in the brain. The idea is first, to be aware of all the behaviors involved. It's called introspection and control and that of course, involves the conscious mind and a unicameral brain.

Prior to mankind gaining conscious awareness the bicameral brain could only change/adapt via fear of survival.

Whether one has a bicameral brain or a unicameral brain...those ole connections have always been problematic. Even if you have learned or desire a new behavior, mental or physical, for at least a time, there is no guarantee the signal will always go where you intended, (so to speak). In the brain, the more a connection is used the less resistance be encountered. Same goes for electrical circuits.