"It is critical that people understand the relationship between pain and depression so that if they are suffering, they can talk to their physician about both their mood and their painful physical symptoms. This will give them the best chance for getting effective treatment," said Rollin "Mac" Gallagher, M.D., M.P.H., a professor of psychiatry, anesthesiology, and public health at the Medical College of Pennsylvania and a member of the executive committee of the board of the National Pain Foundation.