A systematized delusion a group of delusions that are organized around a common theme. This is typical of delusional disorders or paranoid schizophrenia. A researcher, Emil Kraepelin, explained "paranoia" as a continuous systematized delusion arising much later in life with no presence of hallucinations. For instance, a person grows older and starts to believe that family members are conspiring against them to get their money and possessions. This leads to a paranoia (systematized delusion) that revolves around family members.