by Allison Loftus   What is depression?  According to the National Institute of Mental Health, depression can be generalized as feelings of sadness that interfere with daily activities (National Institute of Mental Health (NIMH), 2015). There are several different categories of depression that differ in their severity and symptoms. Some categories of depression include: major depression, persistent depressive disorder, psychotic depression, postpartum and seasonal affective disorder. Major depression shows severe symptoms that interfere with daily activities like the ability to sleep...