Please explain why does depression cause severe feelings of guilt?

Because: Depression can significantly distort our view of the world. One may assume that they are responsible for negative outcomes that they have nothing to do with. They may blame themselves for things outside their scope of influence - even if it is irrational.

Agree with Dr Fowler: In addition, 1 explanation of depression is that it is anger turned inward. The person may b angry with others in their life, but afraid2 express the anger. They work hard not2 feel the negative feelings 4 which they feel guilty. In therapy, it is helpful 2 explore the negative feelings which cannot harm anyone but the person who is suffering from the depression. Anger is not = 2 acting out anger.