Alex is definitely right. The immune system is KING. It's all about survival... CBT is about changing your thought patterns. Changing your thought patterns will "rewire" or "reorganize" your brain. CBT uses the plastic properties of the brain to make changes; so does learning experiences and visualization. None of this will make dead neurons come alive though. The big question is how much damage has been done to brain from factors such as inflammation, oxidative stress, exicotoxicity, toxins, hypoxia and ischemia.