Fr. Culligan explains that a clinically depressed person has a loss of energy and pleasure in most things, including hobbies and sex. The sufferer will sometimes exhibit a dysphoric mood (think Eeyore) or psychomotor retardation. The person in the midst of a dark night experiences loss, too, but more as a loss of pleasure in the things of God. Culligan can often tell the difference between the two based on his response to the person with whom he’s interacting. After listening to a depressed person, he often becomes depressed, helpless, and hopeless himself. He feels the rejection of self, as if the depression is contagious. In contrast, he is not brought down when people speak of a spiritual aridity.
I found this paragraph in Culligan’s chapter to be especially helpful:
“In the dark night of spirit, there is painful awareness of one’s own incompleteness and imperfection in relation to God; however, one seldom utters morbid statements of abnormal guilt, self-loathing, worthlessness, and suicidal ideation that accompany serious depressive episodes. Thoughts of death do indeed occur in the dark night of the spirit, such as ‘death alone will free me from the pain of what I now see in myself,’ or ‘I long to die and be finished with life in this world so that I can be with God,’ but there is not the obsession with suicide or the intention to destroy oneself that is typical of depression. As a rule, the dark nights of sense and spirit do not, in themselves, involve eating and sleeping disturbances, weight fluctuations, and other physical symptoms (such as headaches, digestive disorders, and chronic pain).”
