Intermetamorphosis is a delusional misidentification syndrome

Delusional misidentification syndrome

Delusional misidentification syndrome is an umbrella term, introduced by Christodoulou for a group of delusional disorders that occur in the context of mental or neurological illness. They all involve a belief that the identity of a person, object or place has somehow changed or has been altered...

, related to agnosia

Agnosia

Agnosia is a loss of ability to recognize objects, persons, sounds, shapes, or smells while the specific sense is not defective nor is there any significant memory loss...

. The main symptoms consist patients believing that they can see others change into some one else both external appearance and internal personality. The disorder is usually comorbid

Comorbidity

In medicine, comorbidity is either the presence of one or more disorders in addition to a primary disease or disorder, or the effect of such additional disorders or diseases.- In medicine :...

 with neurological disorder

Neurological disorder

A neurological disorder is a disorder of the body's nervous system. Structural, biochemical or electrical abnormalities in the brain, spinal cord, or in the nerves leading to or from them, can result in symptoms such as paralysis, muscle weakness, poor coordination, loss of sensation, seizures,...

s or mental disorders.

An example from medical literature is a man who was diagnosed with Alzheimer's disease

Alzheimer's disease

Alzheimer's disease also known in medical literature as Alzheimer disease is the most common form of dementia. There is no cure for the disease, which worsens as it progresses, and eventually leads to death...

. After some time he mistook his wife for his deceased mother and later for his sister. As an explanation, he stated that he had never been married or that his wife had left him. Later he mistook his son for his brother and his daughter for another sister. Visual agnosia or prosopagnosia

Prosopagnosia

Prosopagnosia is a disorder of face perception where the ability to recognize faces is impaired, while the ability to recognize other objects may be relatively intact...

were not diagnosed, as the misidentification also took place during phone calls. On several occasions he mistook the hospital for the church he used to go to.

The disorder was first described in 1932 by P. Courbon and J. Tusques (Illusions d'intermétamorphose et de la charme ).