Cotard delusion is a mental health condition where someone believes they are dead, or no longer exist. It can cause people to think that their body parts are missing, or that they have lost the ability to think or feel emotions. It can also cause people to have strong feelings of guilt, shame or despair. To someone with Cotard delusion, the world may seem like a dark and hopeless place. Treatment for Cotard delusion includes medicines, psychotherapy, and supportive care.