QUOTE : PSYCHOSIS: A severe mental disorder, a derangement of personality. Some individuals experience mood swings and agitation, but emotional dampening and social withdrawal are the most common symptoms. Despite society’s beliefs, psychotic individuals rarely become violent and are often at a much greater risk of causing harm to themselves than to others.8 There are many theories as to what causes psychosis. Many current theories agree that it is caused by a combination of inherited genetic factors and external environmental factors.