How negative thinking changes our brain for the worse - and what we can do to fix it

'Sticks and stones may break our bones but words will never hurt us.' It's a popular school ground rhyme but the reality is that words can and do hurt us and sometimes they hurt us simply because we allow them to. Dr. Phil explains how constantly dwelling on the negative things that have been said to us will even change our brain.  But there is good news as we can actually change our internal dialogue with some simple steps!