paranoia (prˌənoiˈə) [key], in psychology, a term denoting persistent, unalterable, systematized, logically reasoned delusions, or false beliefs, usually of persecution or grandeur. In the former case the paranoiac creates a complex delusional system that purports to show that people want to hurt him; in the latter, he sees himself as an exalted person with a mission of great importance. Other types of delusions include somatic delusions, as in the case of hypochondria, and jealous delusions. The term paranoia was first used by German psychiatrist Karl L. Kahlbaum in 1863. The condition, often known as delusional disorder, is found among individuals suffering from paranoid schizophrenia, paranoid personality disorder, and any of several paranoid disorders. Minor instances of paranoia are also commonly found among older people. Most individuals who suffer from some form of paranoia tend to be suspicious of the motives of others, leading them to be hypersensitive, tense, and argumentative. Jealousy and vengeful emotions are also common, and can lead to violent confrontation in the most severe cases. In most paranoid delusions, the individual believes that there is a pattern to random events which is somehow connected to him. Individuals with paranoid schizophrenia often suffer from delusions in conjunction with more severe symptoms, such as hallucinations.