Clinical lycanthropy

Clinical lycanthropy is defined as a rare psychiatric syndrome that involves a delusion that the affected person can transform into, has transformed into, or is, an animal. Its name is associated with the mythical condition of lycanthropy, a supernatural affliction in which humans are said to physically shapeshift into wolves. It is purported to be a rare disorder.
Signs and symptoms.
Affected individuals believe that they are in the process of transforming into an animal or have already transformed into an animal. It has been associated with the altered states of mind that accompany psychosis (the 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 reported on a series of cases and proposed some diagnostic criteria by which lycanthropy could be recognised:
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 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 behavioral 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 a hyena, cat, horse, bird or tiger has been reported on more than one occasion. Transformation into frogs, and even bees, has been reported in some instances. In Japan, transformation into foxes and dogs was usual (, ). 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".
There is a case study of a psychiatric patient who had both clinical lycanthropy and Cotard delusion. The term "ophidianthropy" refers to the delusion that one has been transformed into a snake. Two case studies have been reported.
Proposed mechanisms.
Clinical lycanthropy is a very 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 conditions and cultural influences may result in the expression of the human-animal transformation theme that defines the condition.
Neurological factors.
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 and 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.
Related disorders.
In rare cases, individuals may believe that other people have transformed into animals. This has been termed "lycanthropic intermetamorphosis" and "lycanthropy spectrum". A 2009 study reported that, after the consumption of the drug MDMA (Ecstasy), a man displayed symptoms of paranoid psychosis by claiming that his relatives had changed into various animals such as a boar, a donkey and a horse.
History.
Catherine Clark Kroeger has written that several parts of the Bible refer to King Nebuchadnezzar's behavior in the book of Daniel 4 as a being manifestation of clinical lycanthropy. Neurologist Andrew J. Larner has written that the fate of Odysseus's crew due to the magic of Circe may be one of the earliest examples of clinical lycanthropy.
It is believed that the king of Armenia, Tiridates III, also suffered from this disorder. He was cured by Gregory the Illuminator.
According to Persian tradition, the Buyid prince Majd ad-Dawla was suffering from an illusion that he was a cow. He was cured by Avicenna.
Notions that lycanthropy was due to a medical condition go back to the seventh century, when the Alexandrian physician Paulus Aegineta attributed lycanthropy to melancholia or an "excess of black bile". During 1563, a Lutheran physician named Johann Weyer wrote that werewolves suffered from an imbalance in their melancholic humour and exhibited the physical symptoms of paleness, "a dry tongue and a great thirst" as well as sunken, dim and dry eyes. Even King James VI and I in his 1597 treatise "Daemonologie" does not blame werewolf behaviour on delusions created by the Devil but "an excess of melancholy as the culprit which causes some men to believe that they are wolves and to 'counterfeit' the actions of these animals". The perception of an association between mental illness and animalistic behaviour can be traced throughout the history of folklore from many different countries.
Case example.
A 20-year old man was admitted to a mental hospital due to his increasingly agitated and erratic behaviors. During his initial evaluation, he was guarded and preoccupied. He had no previous psychiatric history. Over the next few days, he displayed increasingly psychotic, animal-like behaviors. These behaviors included howling loudly, running abruptly, and crawling on all fours. He appeared to be internally stimulated. When asked about these behaviors, he was initially evasive but eventually admitted that he believed he was a werewolf and would periodically transform into a wolf. He started believing this after having visions of "the Devil" years before and reported hearing random voices. The patient was started on ziprasidone and his symptoms gradually responded and his animal-like behaviors eventually ceased all together.