Clinical lycanthropy is defined as a rare psychiatric syndrome which involves a delusion that the affected person can or has transformed into an animal, or that he or she is an animal. Its name is connected to the mythical condition of lycanthropy, a supernatural affliction in which people are said to physically shape shift into wolves. The word zoanthropy is also sometimes used for the delusion that one has turned into an animal in general and not specifically a wolf.
Affected individuals report a delusional belief that they have transformed, or are in the process of transforming into another 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 behaviour of the affected person.
A study on lycanthropy from the McLean Hospital reported on a series of cases and proposed some diagnostic criteria by which lycanthropy could be recognised:
- A patient reports in a moment of lucidity or looking back he sometimes feels as an animal or has felt like one.
- A patient behaves in a manner that resembles animal behaviour, for example crying, grumbling or creeping.
According to these criteria, either a delusional belief in current or past transformation, or behaviour 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 there is no specific diagnosis of mental or neurological illness associated with its behavioural consequences.
It also seems that lycanthropy is not specific to an experience of human-to-wolf transformation; a wide variety of creatures have been reported as part of the shape-shifting experience. A review of the medical literature from early 2004 lists over thirty published cases of lycanthropy, only the minority of which have wolf or dog themes. Canines are certainly not uncommon, although the experience of being transformed into hyenas, cats, horses, birds and tigers has been reported on more than one occasion. Transformation into frogs, and even bees, has been reported in some instances. A 1989 case study described how one individual reported a serial transformation, experiencing a change from human, to dog, to horse, and then finally cat, before returning to the reality of human existence after treatment. There are also reports of people who experienced transformation into an animal only listed as 'unspecified'.
Clinical lycanthropy is a rare condition and is largely considered to be an idiosyncratic expression of a psychotic-episode caused by another condition such as schizophrenia, bipolar disorder or clinical depression.
However, there are suggestions that certain neurological and cultural influences may lead to the expression of the human-animal transformation theme that defines the condition.
One important factor may be differences or changes in parts of the brain known to be involved in representing body shape (e.g. see proprioception, body image). 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 sifted through cultural traditions and ideas.
Cultural influences are thought to strongly influence the content of psychosis and psychosis-like experiences and we have a large cultural resource when it comes to human-to-animal transformation, as many societies have included this concept into myths, stories, or rituals (see lycanthropy for many such examples). There have also been cases of feral children seemingly raised by animals after losing their parents. Psychiatrist Lucien Malson collected more than fifty alleged cases in his landmark book Wolf Children and the Problem of Human Nature. More cases have been reported since its publication in 1964, suggesting that some beliefs about lycanthropy might stem from observations of unusual maternal relationships between humans and animals.
While mainstream psychiatry assumes that someone who believes themselves to be an animal is mentally ill, someone who deliberately tries to accomplish the same with psychoactive potions and ritual is considered a shaman in many societies around the world.
In earlier times the state of the patient was commonly explained as due to possession. Marcellus of Sida reported that in Greece the patients frequented the tombs at night, and that they were recognizable by their yellow complexion, hollow eyes and dry tongue. The Garrows of India are said to tear their hair when they are seized with the complaint, which is put down to the use of a drug applied to the forehead; this recalls the stories of the witch's salve in Europe. In Abyssinia the patient is usually a woman; two forms are distinguished, caused by the hyena and the leopard respectively. A kind of trance ushers in the fit; the fingers are clenched, the eyes glazed and the nostrils distended; the patient, when she comes to herself, laughs hideously and runs on all fours. The exorcist is a blacksmith; as a rule, he applies onion or garlic to her nose and proceeds to question the evil spirit.