s lycanthropes as suffering from any of the five conditions; Rabies, Porphyria, Hypertrichosis, Body Image Distortion and psychological illness.
A strain of virus carried by dogs, wolves and other animals including vampire bats causes Rabies. The virus strikes the central nervous system and produces uncontrollable excitement and painful contractions of the throat muscles’ intervention preventing the victim from drinking. Usually the patient dies within three or four days of first symptom.
The second disease, Porphyria is a rare genetic disorder that results in a deficiency of heme, one of the pigments in the oxygen-carrying red blood cells. At the 1985 conference of the American Association for the Advancement of Science, biochemist David Dolphin suggested that the untreated symptoms of Porphyria match many of the traits associated with the classic lycanthrope. One of them is severe photosensitivity, which makes venturing out into daylight extremely painful and thus dooms the sufferer to a life of shadows and darkness. As the condition advances, the victim’s appearance grows increasingly morbid; discoloration of the skin and an unusual thick growth of facial or body hair occurs. There is a tendency for an abnormal change in skin and formation of sores. Eventually the disease attacks cartilage (the soft bone) and causes a progressive deterioration of the nose, ears, eyelids and fingers. The teeth, as well as the fingernails and the flesh beneath them might turn red or reddish brown because of deposition of Porphyrin, a component of Hemoglobin in the blood. Porphyria is often accompanied by mental disturbance, from mild hysteria to delirium and manic-depressive psychoses.
The third disease Hypertrichosis is also known as "Wolfitis", refers to a condition of excessive body hair growth. In most cases, the term is used to refer to an above-average amount of normal body hair that is unwanted and is an aspect of human variability. The hair growth can be generalized, symmetrically affecting most of the torso and limbs, or localized, affecting a particular area of skin. Though severe Hypertrichosis is quite rare it results in excessive or animal-like hair on face and body.
Defect in the part of the brain known to be involved in representing body shape causes body image distortion. A neuroimaging study of two people diagnosed with clinical lycanthropy showed that these areas display unusual activation, suggesting that when people report their bodies are changing shape, they may be genuinely perceiving those feelings. Body image distortions are not unknown in mental and neurological illness, so this may help explain at least part of the process. One further puzzle is why an affected person doesn't simply report that their body "feels like it is changing in odd ways", rather than presenting with a delusional belief that they are changing into a specific animal. There is much evidence that psychosis is more than just odd perceptual experiences so perhaps lycanthropy is the result of these unusual bodily experiences being understood by an already confused mind, perhaps filtered through the lens of cultural traditions and ideas.
Psychologists have concluded that lycanthropes are actually patient of psychiatric syndrome that involves a delusional belief that the affected person is, or has, transformed into an animal. It has been linked with the altered states of mind that accompany psychosis (the reality-bending mental state that typically involves delusions and hallucinations) with the transformation only seeming to happen in the mind and behavior of the affected person.
A study on lycanthropy from the McLean Hospital in New York reported on a series of cases and proposed some diagnostic criteria by which lycanthropy could be classified:
According to these criteria, either a delusional belief in current or past transformation, or behavior that suggests a person thinks of themselves as transformed, is considered evidence of clinical lycanthropy. The authors go on to note that although the condition seems to be an expression of psychosis