Shared delusion Health Dictionary

A fixed, irrational idea not shared by others and not responding to reasoned argument. The idea in a paranoid delusion involves persecution or jealousy. For instance, a person may falsely believe that he or she is being poisoned (see paranoia). Persistent delusions are a sign of serious mental illness, most notably schizophrenia and manic–depressive illness. (See also hallucination; illusion.)... delusion

An irrational and usually unshakeable belief (idée ?xe) peculiar to some individuals. They fail to respond to reasonable argument and the delusion is often paranoid in character with a belief that a person or persons is/are persecuting them. The existence of a delusion, of such a nature as to in?uence conduct seriously, is one of the most important signs in reaching a decision to arrange for the compulsory admission of the patient to hospital for observation. (See MENTAL ILLNESS.)... delusions

The coordinated, or otherwise explicitly agreed upon, sharing of responsibility for provision of medical or nonmedical services on the part of two or more otherwise independent hospitals or health programmes.... shared services

a *monodelusional disorder in which patients believe they or their environment are infested by living or non-living pathogens. These can range from rats in the patient’s house to microspores in the air. Most commonly, patients claim they are infested with insects, worms, parasites, mites, or inanimate threads or fibres, often underneath their skin. Many present the alleged parasite as a specimen for examination. If compliance can be established, most patients respond well to *antipsychotic medication. The term delusional infestation was first introduced by Roland W. Freudenmann and Peter Lepping in 2009, and has gradually superseded the terms delusional parasitosis and Ekbom’s syndrome.... delusional infestation

the intensity with which a delusional belief is held. This can vary over time and sometimes shifts quite rapidly. Some factors, such as treatment, may temporarily or permanently reduce the intensity of a delusion, while others may work to reinforce it.... delusional intensity

a *delusional belief that one’s partner is unfaithful when there is no reasonable evidence for this. It often occurs in the context of *alcoholism.... delusional jealousy

see delusional infestation.... delusional parasitosis

a *Schneiderian first-rank symptom in which a person believes that a normal percept (product of perception) has a special meaning for him or her. For example, a cloud in the sky may be misinterpreted as meaning that someone has sent that person a message to save the world. While the symptom is particularly indicative of *schizophrenia, it also occurs in other psychoses, including *mania (in which it often has grandiose undertones).... delusional perception

a delusion in which the patient believes that another person or an animal (usually the patient’s pet) has certain physical symptoms, even though these cannot be objectively verified. The patient with the delusional belief is called the inducer; the person or pet that is allegedly affected is the proxy. Some *monodelusional disorders, such as *delusional infestation, have a prevalence of delusion by proxy of up to 5%. Treatment is usually with *antipsychotics. In some situations it may be necessary to remove the proxy to provide safety from the behaviour associated with the delusion. See also double delusion; folie à deux.... delusion by proxy

a *delusion in which the patient believes that unsuspicious occurrences refer to him or her in person. Patients may, for example, believe that certain news bulletins have a direct reference to them, that music played on the radio is played for them, or that car licence plates have a meaning relevant to them. Ideas of reference differ from delusions of reference in that insight is retained.... delusion of reference

the situation in which a patient (the inducer) presents with delusional symptoms that he or she believes to be shared by someone else who is incapable of expressing them (typically a child or a pet). This is different from a *delusion by proxy, in which the inducer does not claim to be experiencing the symptoms himself or herself. The term was introduced in 2015 by Peter Lepping, Mark Rishniw, and Roland Wolfgang Freudenmann. Compare folie à deux.... double delusion