CNN  —  Long working hours might not just be bad for you, they could also be altering the structure of your brain, a new study suggests. The research , published Tuesday, found “significant changes” in the brains of people who were overworking, which is a combination of physical and emotional overexertion, as well as a lack of rest. The research was conducted by two scientists at South Korea’s Chung-Ang University and Yonsei University, who followed 110 healthcare workers classified into “