Depression

Inability to feel any emotion, even sadness. Your mind has dealed with so much misery, that it becomes numb to the emotional pain and feels nothing. Because if this lack of feeling, they are separated from the rest of humans because are ability to be aware of our emotions makes us special. This separation leads to a vague loneliness and the depressed person might find themselves stuck in a black, endless void where their happiness, sadness, anger, excitement, etc used to be. Because of this habitation in this entry void, the depressed person might find life worthless, and may not want to live anymore.