Negative emotions rebound in the body. The psychosocial burden of harmful thoughts in the form of stress or depression can even be measured in the laboratory.
The good news is that getting out and thinking positively can be learned.
One person who should know is Derick Howell. He is a specialist in highly effective programs against anxiety, stress, and panic. He regularly coaches executives who need a lot of positive thinking as fuel on their way to the top.
He is now making his best strategies for positive thinking available to a wide audience in book form: