Patients with acute delusions of persecutory type almost always experience anxiety. Delusions of grandeur mostly occur in a manic state in which, by definition, an elevated mood is present. Depression leads to certain types of delusions, such as nihilistic and hypochondric delusions, as well as delusions of sin, guilt, and poverty. A peculiar kind of love seems to be the root of DeClerambault's syndrome, the delusion of being loved by another person, and delusions of jealousy seem to be motivated by some mixture of love and distrust. In short: There seems to be a relationship between emotions and delusions. What kind of relationship is this? Do disturbed emotions lead to the development of delusions or do delusions lead to disturbed emotions? What evidence can be derived from the literature in support of the theories which have been proposed about such relationships?