Depressed people may be preoccupied with, or ruminate over, thoughts and feelings of worthlessness, inappropriate guilt or regret, helplessness, hopelessness, and self-hatred.[23] In severe cases, depressed people may have symptoms of psychosis. These symptoms include delusions or, less commonly, hallucinations, usually unpleasant.[24] Other symptoms of depression include poor concentration and memory (especially in those with melancholic or psychotic features),[25] withdrawal from social situations and activities, reduced sex drive, irritability,[26] and thoughts of death or suicide. Insomnia is common among the depressed.