Suppose a person has been diagnosed with severe Clinical Depression and has been undergoing treatment for that depression for years if not decades with minimum improvement. The person has some good days; some not so good.
Given that medically speaking, depression is a real sickness just like any other sickness like cancer or heart disease or the like, if a person is having a not-so-good day, would this be sufficient reason to stay home from mass; i.e., the person “just doesn’t feel like going?”
When symptoms from more “visible” ailments act up, it is usually justifiable for a person to miss mass. Why would depression be any different?