DELUSION

in psychology, absolute conviction, often preoccupying, that is characterized as idiosyncratic, of personal significance to the deluded individual, and persistent despite logical absurdity or contradictory evidence. Delusions are symptomatic of such mental disorders as paranoia, schizophrenia, and major depression and of such physiological conditions as senile psychosis and delirium. They vary in intensity, extent, and coherence and may represent pathological exaggeration of normal tendencies to rationalization, wishful thinking, and the like. Among the most common are delusions of persecution and grandeur (see paranoia); others include delusions of disease (hypochondriasis, q.v.), guilt, erotic delusions (e.g., that one is loved by some famous person), and delusions of control.