The attached article contains a map of the 48 states that will give you an understanding as to which regions of the United States produced the highest number of men who were able to pass their Selective Service physical examinations, and which parts of the nation provided men who could not pass these examinations.
Mental health was not screened at that time - in fact, it was later discovered that a full sixty percent of the invalided Doughboys were mentally deficient, and the Army was unable to screen them out - you can read about that here
