“Jikoshu”: Japanese studies in the 1960s and 1970s, and international trends today

Abstract In the 1960s and 1970s, there was widespread discussion in Japan about the pathological experience of “unpleasant odors emanating from one's body.” This symptom is called “Jikoshu,” and this term was used in combination with various words, such as “Genkaku” (hallucination) and “Moso” (delusion), reflecting its symptomatological ambiguity. The best‐known term in the English‐language literature is Jikoshu‐Kyofu (Jikoshu phobia). By further abstracting this symptom and viewing it as a delusion‐like experience of “something leaking out of me,” egorrhea syndrome (Fujinawa) was proposed, which was considered to be partly a pathology of schizophrenia. Similar cases were characteristically observed during adolescence, and a study emerged suggesting that the syndrome was “adolescent paranoia” (Murakami), distinct from schizophrenia. However, the terms “Jikoshu‐Taiken” (Jikoshu experience; Kasahara et al.) and “Jikoshu‐Sho” (Jikoshu syndrome; Miyamoto) were proposed to emphasize the nosological ambiguity. Considered a culture‐bound syndrome unique to Japan or East Asia, Jikoshu received little attention in the English‐language literature apart from a 1971 study of olfactory reference syndrome (Pryse‐Phillips), which presents with similar symptoms. In recent years, research has placed this disorder within the obsessive‐compulsive spectrum, and it has been adopted as an ICD‐11 disorder under the term “olfactory reference disorder.”


INTRODUCTION
In the 1960s and 1970s in Japan, the pathological experience of "unpleasant odors emanating from one's body" was widely discussed.
In a typical Jikoshu case, the patient begins to think, "People around me somehow seem to be avoiding me.When I approach them, they bring their hands to their noses, frown, or move away from me.
There must be some kind of a bad smell coming out of my body."The symptoms persist for a long time.The patient might become extremely worried and seek self-care to eliminate the odor or seek treatment for an illness that they believe is the cause of the odor. 2 The psychopathological study of Jikoshu began in 1961 with Hiroshi Adachi's case study 3 regarding the symptom "I am emitting disgusting odors," and was followed by many reports from various viewpoints during the 1960s and 1970s.These subsequent discussions reflected several views, including that the symptom is a phobia or obsession with one's own body odor, that the symptom represents a delusion about body odor with the overall picture seen as an adolescent psychosis distinct from schizophrenia, and that the condition is a unique clinical entity related to smell and cannot be dismissed as a hallucination or delusion.5][6] The aim here is to introduce Jikoshu studies from the 1960s and 1970s, touching on concepts such as egorrhea syndrome, adolescent paranoia, and Jikoshu-Sho while also referring to recent international trends.

JIKOSHU AS A PHOBIA
If the symptom "I am emitting an unpleasant odor" is described without diagnostic prejudice, it would be called Jikoshu-Taiken (selfodor experience).However, this experience was initially considered a symptom of Taijin-Kyofu (or Taijin-Kyofu-Sho).Although similar to social anxiety disorder, Taijin-Kyofu is a clinical entity unique to Japan and already discussed to some extent in English-language literature.According to Takahashi, 7 the term Taijin-Kyofu first appeared in Morita's 1932 article "Erythrophobia (or Taijin-Kyofu) and its treatment." 8Morita described "fear of shame" as a derivative of erythrophobia: "Recently, someone had named this fear of shame Taijin-Kyofu."Morita's fear of shame or Taijin-Kyofu described cases of anguish and pessimism about one's cowardice and shyness.In 1938, Takara 9 included in Taijin-Kyofu those cases involving relational ideation, such as "fear of self-facial expression," in which one's odd and unpleasant facial expressions is perceived to cause discomfort in others and others are experienced as having unpleasant facial expressions.From the 1950s onward, a series of articles was published on the relationship between Taijin-Kyofu and Japanese social culture, which spread understanding of Taijin-Kyofu as a uniquely Japanese neurosis.
Subsequently, similarities between Taijin-Kyofu and DSM (Diagnostic and Statistical Manual of Mental Disorders) 10,11 social anxiety disorder were recognized, and so recent descriptions of Taijin-Kyofu were likely written with DSM social anxiety disorder in mind.
However, as the concept of social anxiety disorder was introduced to Japan, it was realized that there were two subtypes of Taijin-Kyofu. 12One subtype is generally equivalent to the DSM concept, 10,11 which Nagata et al. 13 termed the typical subtype.The other is what they called the offensive subtype, which is more in line with the older description in Taijin-Kyofu (Table 1 briefly summarizes the characteristics of the offensive subtype according to Yamashita 12 ).
For example, Shinfuku's 1958 textbook 14 states the following: "In our country, there are often patients who have a pathological fear and avoidance of going out in public, being in public, and interacting with others, collectively referred to as Taijin-Kyofu.The basis of this symptom varies from case to case, but can be broadly classified into the following categories: fear of looking at others (Jiko-Shisen-Kyofu), fear of one's own face (blushing, etc.) and attitude (erythrophobia, fear of getting nervous), and fear of unpleasant body odor (Jikoshu-Kyofu)."Whereas social anxiety disorder is a problem of anxiety in social situations, Shinfuku's description suggests that the core of Taijin-Kyofu is a phobia of various phenomena that occur in interpersonal situations, with Jikoshu-Kyofu occupying a significant part of the picture.This type of fear, also referred to as the offensive-type of Taijin-Kyofu, is the fear that certain features of the patient might be objectionable or harmful to society.As mentioned above, Japanese textbooks from the mid-20th century indicate the offensive-type was considered the essence of Taijin-Kyofu.In fact, the offensive-type was considered a culture-bound syndrome characteristic of East Asia.Although some studies have suggested the specific involvement of cultural characteristics, 15 others considered the offensive-type not so different from social anxiety disorder. 16,17In one study, avoidance of eye contact was associated with social anxiety disorder, 18 whereas in another study, Jiko-shisen-Kyofu not Taijin-Kyofu was considered specific to East Asia. 19There might be a growing recognition that Taijin-Kyofu and social anxiety disorder reflect different facets of a single clinical entity.However, this paper will focus on the issue of smell, without expanding on this issue too much.

EGORRHEA SYNDROME AND ADOLESCENT PARANOIA: JIKOSHU AS A DELUSION
In 1962, 20 Akira Fujinawa and his colleagues coined the term "egorrhea" in their study of the Jikoshu experience, which encompasses a group of symptoms in which "something leaks out from oneself and becomes known to others or affects others." 21To our knowledge, the term's earliest mention in the literature was in 1967, 22 when Fujinawa proposed the term "egorrhoe" to signify that something in the ego leaks out, following the example of rhinorrea, liquorrhea, or logorrhea.However, given the term's Germanic spelling, "egorrhea" is more appropriate in English.
Patients with Jikoshu have delusional beliefs that their bodies emit unpleasant odors that cause others to dislike and avoid them.
T A B L E 1 Characteristics of offensive-type of Taijin-Kyofu (Yamashita). 12Firm belief in the existence of serious shortcomings (such as flushing, bodily odors).2. Its existence is intuitively perceived by patients from the behavior, actions, and gestures of other people around them. 3.These defects make others to feel unpleasant and therefore must be corrected or removed.4. No other symptoms appear in the long follow-up period of time.
Over the years, symptoms in no small number of patients persist without developing into other psychiatric conditions.These constant symptoms include (a) the delusion of soliloquy, in which the patient complains that they have spoken to themself unknowingly in public and that people know what they are thinking, (b) the delusion of talking in one's sleep, in which the patient says they have spoken secrets aloud in their sleep, and (c) a kind of thought broadcasting, in which the patient's thoughts leak out by themselves and are transmitted to others and become known.This series of symptoms has an experiential structure that can be summarized by the formula "something leaks out from oneself and is known to others or affects others."This something might be a selfodor, a soliloquy, sleep-talk, or thought content.In mild cases it may be a blush, an ugly facial expression, or one's own gaze.Fujinawa considered these a series of clearly outlined symptoms that he called the egorrhea syndrome.
Egorrhea symptoms are found in a variety of disorders, but Fujinawa termed those found in schizophrenia "egorrhea schizophrenia," the characteristics of which are summarized in Table 2. 20 In presenting this concept, Fujinawa attempted to dichotomize schizophrenia into two series, one centered on "syndrome of influence" and the other on egorrhea syndrome.The term syndrome of influence is derived from délire dꞌinfluence in French psychiatry, which means "delusion characterized by the belief that outsiders exert an occult influence on the patient." 23 The symptoms that comprise egorrhea syndrome are delusional beliefs that something is leaking from oneself, therefore Jikoshu in this syndrome would also be considered a delusion.Although egorrhea syndrome can be seen in various mental disorders, Fujinawa seemed to be most concerned with schizophrenia.On the other hand, Murakami's group, contemporaries of Fujinawa, regarded similar symptoms as a delusional syndrome distinct from schizophrenia.
Murakami's group began their research around 1964 by distinguishing schizophrenia from Jikoshu experience, fear of looking at others, and dysmorphophobia, which their colleagues had diagnosed as schizophrenia or early-stage schizophrenia at that time. 24Given that most cases with these symptoms occurred in adolescence and involved adolescent mentality, the condition was thought to have an affinity with paranoia, so it was named adolescent paranoia. 25Table 3 shows clinical features of adolescent paranoia according to Murakami. 24He states that adolescent paranoia has a wide range of adjacent pathologies, from neurotic to psychotic disorders.As a hypochondriasis, it exhibits a unique pathology specific to interpersonal situations, it is distinguished from phobia and obsessive-compulsive disorder by its certainty, it has continuity with Taijin-Kyofu in the dependence of symptoms on interpersonal situations but is distinguished from Taijin-Kyofu by the presence of delusions of reference, the delusions of reference seen in this condition are limited to the patient's physical abnormalities and differ from delusions in schizophrenia, its monosymptomatic delusions are similar to those of delusional disorders but without systematic development, and the guilt expressed in this condition is not a feeling of guilt for one's actions, as in depression, but a feeling of being sorry because one's physical defects cause discomfort in others. 24Thus, Murakami concluded that adolescent paranoia is a clinical entity with a relatively clear symptom profile and stable structure, although it exhibits a "borderline nature" that is close, but not identical to, other diseases.
To summarize the studies presented in this section, the issue of Jikoshu and its proximate pathology's transition to schizophrenia was addressed by the egorrhea syndrome studies, and their close association with adolescent psychology was addressed by the adolescent paranoia studies.

NOSOLOGICAL SINGULARITY OF JIKOSHU
In Tadao Miyamoto's 1976 article, 2 he noted that contemporaneous studies in different countries showed a considerable nosological spread.Whereas the Japanese studies described above considered Jikoshu to be in proximity to Taijin-Kyofu, in Germany Jikoshu was explained in relation to schizophrenia [26][27][28] or cerebral organic diseases, 29 and in France it was contrasted with neurasthenia or melancholy. 30,31A B L E 2 Characteristics of egorrhea schizophrenia (Fujinawa). 20,21 Primarily thought broadcasting, thought echoing, delusions of sleep-talking, and delusions of soliloquies, with transient Jikoshu-Kyofu and Jiko-Shisen-Kyofu.2. No syndrome of influence.
3. With abnormal cenesthesia.4. Associated with guilt theme but no persecution theme.5. Delusions are not systematic.6. Symptoms persist for long periods of time but without a tendency toward personality disorganization.7. Also seen in severe neurosis and borderline cases.
T A B L E 3 Characteristics of adolescent paranoia (Murakami). 24Patients harbor a delusional belief that they cause others discomfort due to certain physical abnormalities of their own, such as their own body odor or the way they look at others.2. As a result, they have delusions of reference (delusions of avoidance), such as being "disliked" or "avoided" by others along with accompanying feelings of guilt.3.These symptoms are situation-dependent and uttered or intensified only in the presence of others.4. Patients generally are willing to be treated, but they seek their perceived abnormalities in physical illness and relentlessly demand corresponding treatment.5. Most cases begin in adolescence, with symptoms monosymptomatic and without personality disorganization.
Fujinawa contrasted egorrhea syndrome with the syndrome influence, although there are other references to similar directions of experience for olfactory symptoms.Miyamoto introduced the terms égocentrique (egocentric) and exocentrique (exocentric) from French psychiatry 30,32 as well as Tellenbach's terms rezeptiv (receptive) and emanativ (emanative). 33As we have seen, the "from-self-tosurroundings" mode of experience or égocentrique/rezeptiv mode is prominent in the Jikoshu experience.On the other hand, in the "fromsurroundings-to-self" mode of experience or exocentrique/emanativ mode odor complaints, for example, are described as "strange smells wafting toward me from the surroundings," with this direction usually observed in delusions of persecution in schizophrenia.This is not to say that there are no exocentric moments in Jikoshu.Many patients first experience exocentric experiences as people around them expressing their discomfort or avoiding them before perceiving their bodies emitting unpleasant odors.In other words, Fujinawa may have considered the pathogenesis of schizophrenia in two directions, whereas Miyamoto emphasized these two directions as inseparably linked in Jikoshu experience.
Jikoshu experience is situation-dependent.The patient is unaffected when alone or with their family and affected only in the presence of classmates, neighbors, or even strangers.The patient with Jikoshu worries about anonymous people, but not other persons of particular significance who are present, as would be the case in the delusions of schizophrenia.Miyamoto believed that this explains why a patient with Jikoshu consistently harbors strong delusional convictions without exhibiting any specific delusional development.
Even so, he presented three types of Jikoshu experiences, with three distinct poles.The first is the hallucination type.Although some researchers 34 attempted to divide Jikoshu experiences into olfactory delusions and olfactory hallucinations, all agree that Jikoshu is not a genuine hallucination but rather a unique experience that is closer to a delusion.Nonetheless, there are cases where the patient clearly states that they can smell their own body.In these cases, egocentric orientation prevails and the patient complains that they can smell themself even when alone.These are transient symptoms with a good prognosis.
The second is the reference type, which is an exemplar of a Jikoshu experience.The mechanism of relating others' reactions to one's own odor is recognized in the establishment of symptoms, with the experience naturally preceded by an exocentric direction.The tendency to self-reference persists but rarely develops into a genuine delusion of reference and lacks the element of olfactory hallucinations.The individual provides their own explanations or interpretations of why body odors occur.These explanations do not deviate greatly from common sense, although in some cases they become bizarre and develop into the next type.
The third is the cenesthetic type.Here, abnormalities of cenesthesia are wide ranging, from mild abnormalities of bodily sensation to cenesthopathy, or from bodily hallucinations to bodily delusions, with all characterized by the addition of bizarre nuances.
The direction of the experience is not clear, with a mixture of egocentric and exocentric directions.Compared with the first two types, patients are often older (30s or older).They look inside their own bodies and attempt to find various explanations for their body odor.Despite their bizarre bodily delusions, their communication is good and they do not speak or act abnormally apart from the subject of Jikoshu.However, they are convinced that their bodies are abnormal, so they visit various departments outside of psychiatry.
They are relentless in their efforts to realize their intentions.For example, a patient who claims that her body odor is caused by odor leaking from a hole in her uterus might seek a gynecologist to remove her uterus.
From this perspective, Miyamoto stated that the Jikoshu experience "remains an entity of psychopathology that is itself extremely significant and has the potential to develop into various pathological phenomena, while maintaining an equidistant relationship with neurosis, schizophrenia, and manic-depressive illness, respectively." 24Thus, he suggested calling the condition Jikoshu-Sho because adding words such as "fear," "hallucination," or "delusion" to a disease that presents with Jikoshu could undermine the totality of this experience.

RISE OF OLFACTORY REFERENCE DISORDER
Like Taijin-Kyofu, Jikoshu-Sho has been considered a culture-bound syndrome unique to Japan or East Asia. 35,36However, Miyamoto noted that descriptions of similar symptoms exist in the German-and French-language literature. 2 In the English-language literature, the earliest reference to this syndrome dates back to 1891. 37However, it seems unlikely that there were no such cases in the West, but without the proper terminology, such cases would be difficult to report.Such a term was first presented in the English-language literature in Pryse-Phillips' 1971 article on olfactory reference syndrome (ORS). 38However, that article initially received little attention: a PubMed search for articles with ORS in the title found only five before 1983, although the number of articles increased after 1997.Suzuki et al. 35 stated that Jikoshu-Kyofu and ORS share a common clinical entity, with ORS considered a counterpart of Jikoshu-Kyofu in the English-language literature.ORS has been defined as a psychiatric condition characterized by persistent preoccupation with body odor accompanied by shame, embarrassment, significant distress, avoidance behavior, and social isolation. 39e revival of ORS is due to the adoption of obsessivecompulsive spectrum disorder (OCSD), 40 Thus, Fujinawa attempted to divide schizophrenia into two symptom clusters: one in which something inside the patient leaks out and harms others, and another in which something outside enters and harms the patient.
proposed by Hollander et al., in the Diagnostic and Statistical Manual of Mental Disorders, 5thedition (DSM-5).In establishing "obsessive-compulsive and related disorders" in the DSM-5, 11 body dysmorphic disorder, hoarding disorder, trichotillomania (hair-pulling disorder), and excoriation were listed as "related disorders" in addition to OCD, with reference to the OCSD concept of preoccupation and repetitive behaviors as the basic pathology.Initially considered for inclusion in the OCD category in the DSM-5,37 ORS was dropped due to lack of evidence establishing it as a separate disorder.ORS was listed with only the remark on