Timothy F. Jones, of the Tennessee Department of Health, recommends the following action be taken in the case of an outbreak:

- Attempt to separate persons with illness associated with the outbreak.

- Promptly perform physical examination and basic laboratory testing sufficient to exclude serious acute illness.

- Monitor and provide oxygen as necessary for hyperventilation.

- Minimize unnecessary exposure to medical procedures, emergency personnel, media or other potential anxiety-stimulating situations.

- Notify public health authorities of apparent outbreak.

- Openly communicate with physicians caring for other patients.

- Promptly communicate results of laboratory and environmental testing to patients.

- While maintaining confidentiality, explain that other people are experiencing similar symptoms and improving without complications.

- Remind patients that rumors and reports of "suspected causes" are not equivalent to confirmed results.

- Acknowledge that symptoms experienced by the patient are real.

- Explain potential contribution of anxiety to the patient's symptoms.

- Reassure patient that long-term sequelae from current illness are not expected.

- As appropriate, reassure patient that thorough clinical, epidemiologic and environmental investigations have identified no toxic cause for the outbreak or reason for further concern.

Some responses by authorities to MPI are not appropriate. Intense media coverage seems to exacerbate outbreaks. Once it is determined that the illness is psychogenic, it should not be given credence by authorities. For example, in the Singapore factory case study, calling in a medicine man to perform an exorcism seemed to perpetuate the outbreak.

The hypothesis that those prone to extroversion or neuroticism, or those with low IQ scores, are more likely to be affected in an outbreak of hysterical epidemic has not been consistently supported by research. Bartholomew and Wesseley state that it “seems clear that there is no particular predisposition to mass sociogenic illness and it is a behavioural reaction that anyone can show in the right circumstances.”

Females are affected with mass psychogenic illness at greater rates than males. Adolescents and children are frequently affected in cases of MPI.

Several criteria are typically used to make a diagnosis of koro. The primary criteria is a patient's report of genital (typically penile or female nipple) retraction despite a lack of objective physical evidence demonstrating retraction. This is accompanied by severe anxiety related to the retraction, fear of death as a result of retraction, and use of mechanical means to prevent retraction. Cases that do not meet all the requirements are generally classified as koro-like symptoms or given a diagnosis of partial koro syndrome. It has been argued that the criteria are sufficient but not necessary to make a diagnosis of koro. Researchers have identified Koro as a possible "cultural relative" of Body Dysmorphic Disorder. DSM-IV explains the process of differential diagnosis between these two disorders.

A full medical, psychosexual and psychiatric history should be documented. The physician should explore the patient’s concerns about appearance and body image (ruling out body dysmorphic disorder). Additionally, the physician should inquire about overall beliefs, personal values, and assumptions that the patient is making about his or her genitals. Given that Koro is often an “attack” with a great deal of associated anxiety, the physician should ascertain the patient’s emotional state along with the timeline from onset to the presentation at the examination.

A physical examination should involve an assessment of overall health along with a detailed genital examination. In men, genital examination should be performed immediately after penile exposure, to avoid changes due to external temperature. The primary intent of the male exam is to exclude genuine penile anomalies such as hypospadias, epispadias and Peyronie's disease. The presence of a significant suprapubic fat pad should be noted as well. Careful measurements of flaccid length, stretched length and flaccid girth will also be useful. If male patients insist that their penis is shrinking and disappearing, measurements after intracavernosal alprostadil may be used in the office to determine the true erect length and to diagnose any penile abnormalities in the erect state. A physical examination should note any injuries inflicted by the patient in an effort to "prevent" retraction as further confirmation of Koro.

The psychological mechanism of conversion can be the most difficult aspect of a conversion diagnosis. Even if there is a clear antecedent trauma or other possible psychological trigger, it is still not clear exactly how this gives rise to the symptoms observed. Patients with medically unexplained neurological symptoms may not have any psychological stressor, hence the use of the term "functional neurological symptom disorder" in DSM-V as opposed to "conversion disorder", and DSM-V's removal of the need for a psychological trigger.

"Jerusalem syndrome as a discrete form, uncompounded by previous mental illness." This describes the best-known type, whereby a previously mentally balanced person becomes psychotic after arriving in Jerusalem. The psychosis is characterised by an intense religious character and typically resolves to full recovery after a few weeks or after being removed from the locality. It shares some features with the diagnostic category of a "brief psychotic episode", although a distinct pattern of behaviors has been noted:

1. Anxiety, agitation, nervousness and tension, plus other unspecified reactions.

2. Declaration of the desire to split away from the group or the family and to tour Jerusalem alone. Tour guides aware of the Jerusalem syndrome and of the significance of such declarations may at this point refer the tourist to an institution for psychiatric evaluation in an attempt to preempt the subsequent stages of the syndrome. If unattended, these stages are usually unavoidable.

3. A need to be clean and pure: obsession with taking baths and showers; compulsive fingernail and toenail cutting.

4. Preparation, often with the aid of hotel bed-linen, of a long, ankle-length, toga-like gown, which is always white.

5. The need to shout psalms or verses from the Bible, or to sing hymns or spirituals loudly. Manifestations of this type serve as a warning to hotel personnel and tourist guides, who should then attempt to have the tourist taken for professional treatment. Failing this, the two last stages will develop.

6. A procession or march to one of Jerusalem's holy places, ex:The Western Wall.

7. Delivery of a sermon in a holy place. The sermon is typically based on a plea to humankind to adopt a more wholesome, moral, simple way of life. Such sermons are typically ill-prepared and disjointed.

8. Paranoid belief that a Jerusalem syndrome agency is after the individual, causing their symptoms of psychosis through poisoning and medicating.

Bar-El et al. reported 42 such cases over a period of 13 years, but in no case were they able to actually confirm that the condition was temporary.

Empirical studies have found that the prognosis for conversion disorder varies widely, with some cases resolving in weeks, and others enduring for years or decades. There is also evidence that there is no cure for Conversion Disorder, and that although patients may go into remission, they can relapse at any point. Furthermore, many patients who are 'cured' continue to have some degree of symptoms indefinitely.

During a period of 13 years (1980–1993) for which admissions to the Kfar Shaul Mental Health Centre in Jerusalem were analysed, it was reported that 1,200 tourists with severe, Jerusalem-themed mental problems were referred to this clinic. Of these, 470 were admitted to hospital. On average, 100 such tourists have been seen annually, 40 of them requiring admission to hospital. About three and a half million tourists visit Jerusalem each year. Kalian and Witztum note that as a proportion of the total numbers of tourists visiting the city, this is not significantly different from any other city.

Historically, misdiagnosis rates have been high due to the complex nature of the disorder although some research now indicates that misdiagnosis may be reducing.

Piblokto is most often found but not confined to the Inughuit culture in the polar regions of northern Greenland. Similar symptoms have been reported in European sailors stranded in Arctic regions in the 1800s. Among the Inughuit, the attacks are not considered out of the ordinary. No native theory of the disorder is currently reported. This condition is most often seen in Inughuit women. Piblokto is most common during long Arctic nights.

Although there is no known cause for piblokto, Western scientists have attributed the disorder to the lack of sun, the extreme cold, and the desolate state of most villages in the region. A reason for this disorder present in this culture may be due to the isolation of their cultural group.

This culture-bound syndrome is possibly linked to vitamin A toxicity (hypervitaminosis A). The native Inughuit diet or Eskimo nutrition provides rich sources of vitamin A through the ingestion of livers, kidneys, and fat of arctic fish and mammals and is possibly the cause or a causative factor. This causative factor is through the disturbance that has been reported for males, females, adults, children, and dogs. The ingestion of organ meats, particularly the livers of some Arctic mammals, such as the polar bear and bearded seal, where the vitamin is stored in toxic quantities, can be fatal to most people.

Inughuit tradition states that it is caused by evil spirits possessing the living. Shamanism and animism are dominant themes in Inughuit traditional beliefs with the angakkuq (healer) acting as a mediator with the supernatural forces. Angakkuit use trance states to communicate with spirits and carry out faith healing. There is a view among the Inughuit that individuals entering trance states should be treated with respect given the possibility of a new "revelation" emerging as a result. Treatment in piblokto cases usually involves allowing the episode to run its course without interference. While piblokto can often be confused with other conditions, (including epilepsy) in which failure to intervene can lead to the victim coming to harm, most cases tend to be more typical.

Recorded incidents of "amafufunyana" appear to have begun in the early 20th century and researchers such as Ngubane "et al" have suggested that its cultural formation may have had something to do with colonialism and migration of indigenous peoples away from their homes. There have also been widespread outbreaks of the condition, similar to events involving contagious spread of hysteria, recorded in the 1980s at a rural girl's boarding school.

The most common types of people that are identified as afflicted by the cultural group are those of the lowest economic and social level and more often during times of cultural hardship and change, such as during migrations. More women than men are also identified.

Research is ongoing in many aspects of functional neurological disorders but large studies are needed to definitely answer key questions including:

What is the best treatment for patients with FND? Even disorders like multiple sclerosis and Parkinson's disease have no definite known cause. The importance of increased awareness in the medical world of what constitutes a positive diagnosis of FND and what the best treatments are may, in the short term, be where research is focused.

Amafufunyana is an unspecified "culture-bound" syndrome named by the traditional healers of the Xhosa people that relates to claims of demonic possession due to members of the Xhosa people exhibiting aberrant behavior and psychological concerns. After study, it was discovered that this term is directed toward people suffering from varying types of schizophrenia. A similar term, ukuthwasa, is used to refer to positive types of claimed possession, though this event also involves those suffering from schizophrenia. It has also found cultural usage among some groups of Zulu peoples.

The direct translation of the term "amafufunyana" is nerves and is a part of a much more complex cultural ideology connecting varying types of psychosis with religious, social, and recently psychiatric beliefs and activities. In a 1998 interview with Xhosa people suffering from schizophrenia by Lund et al., it was determined that through interaction with scientists and psychological services, the preferred treatment for the cultural condition had shifted from relation to traditional healers to active psychiatric assessment.

The Tanganyika laughter epidemic of 1962 was an outbreak of mass hysteriaor mass psychogenic illness (MPI)rumored to have occurred in or near the village of Kashasha on the western coast of Lake Victoria in the modern nation of Tanzania (formerly Tanganyika) near the border of Uganda.

In medicine and medical anthropology, a culture-bound syndrome, culture-specific syndrome, or folk illness is a combination of psychiatric and somatic symptoms that are considered to be a recognizable disease only within a specific society or culture. There are no objective biochemical or structural alterations of body organs or functions, and the disease is not recognized in other cultures. The term "culture-bound syndrome" was included in the fourth version of the "Diagnostic and Statistical Manual of Mental Disorders" (American Psychiatric Association, 1994) which also includes a list of the most common culture-bound conditions (DSM-IV: Appendix I). Counterpart within the framework of ICD-10 () are the "culture-specific disorders" defined in Annex 2 of the "Diagnostic criteria for research".

More broadly, an epidemic that can be attributed to cultural behavior patterns or suggestion is sometimes referred to as a behavioral epidemic. As in the cases of drug or alcohol abuse or smoking, transmission can be determined by communal reinforcement as well as by person-to-person interactions. On etiological grounds, it can be difficult to distinguish the causal contribution of culture in disease from other environmental factors such as toxicity.

Puppy pregnancy syndrome is a psychosomatic illness in humans brought on by mass hysteria.

The syndrome is thought to be localized to villages in several states of India, including West Bengal, Assam, Bihar, Jharkhand, Orissa, and Chhattisgarh, and has been reported by tens of thousands of individuals. It is far more prevalent in areas with little access to education.

People suffering from this condition believe that shortly after being bitten by a dog, puppies are conceived within their abdomen. This is said to be especially likely if the dog is sexually excited at the time of the attack. Victims are said to bark like dogs, and have reported being able to see the puppies inside them when looking at water, or hear them growling in their abdomen. It is believed that the victims will eventually die – especially men, who will give birth to their puppies through the penis.

Witch doctors offer oral cures, which they claim will dissolve the puppies, allowing them to pass through the digestive system and be excreted "without the knowledge of the patient".

Doctors in India have tried to educate the public about the dangers of believing in this condition. Most sufferers are referred to psychiatric services, but in rare instances patients fail to take anti-rabies medication in time, thinking that they have puppy pregnancy syndrome and thus the witch doctor's medicine will cure them. This is further compounded by witch doctors stating that their medicine will fail if sufferers seek conventional treatment.

Some psychiatrists believe that the syndrome meets the criteria for a culture-bound disorder.

Dancing mania (also known as dancing plague, choreomania, St John's Dance and, historically, St. Vitus's Dance) was a social phenomenon that occurred primarily in mainland Europe between the 14th and 17th centuries. It involved groups of people dancing erratically, sometimes thousands at a time. The mania affected men, women, and children who danced until they collapsed from exhaustion. One of the first major outbreaks was in Aachen, in the Holy Roman Empire, in 1374, and it quickly spread throughout Europe; one particularly notable outbreak occurred in Strasbourg in 1518, also in the Holy Roman Empire.

Affecting thousands of people across several centuries, dancing mania was not an isolated event, and was well documented in contemporary reports. It was nevertheless poorly understood, and remedies were based on guesswork. Generally, musicians accompanied dancers, to help ward off the mania, but this tactic sometimes backfired by encouraging more to join in. There is no consensus among modern-day scholars as to the cause of dancing mania.

The several theories proposed range from religious cults being behind the processions to people dancing to relieve themselves of stress and put the poverty of the period out of their minds. It is, however, thought to have been a mass psychogenic illness in which the occurrence of similar physical symptoms, with no known physical cause, affect a large or small group of people as a form of social influence.

The laughter epidemic began on January 30, 1962, at a mission-run boarding school for girls in Kashasha. The laughter started with three girls and spread haphazardly throughout the school, affecting 95 of the 159 pupils, aged 12–18. Symptoms lasted from a few hours to 16 days in those affected. The teaching staff were not affected but reported that students were unable to concentrate on their lessons. The school was forced to close down on March 18, 1962.

After the school was closed and the students were sent home, the epidemic spread to Nshamba, a village that was home to several of the girls. In April and May, 217 people had laughing attacks in the village, most of them being school children and young adults. The Kashasha school was reopened on May 21, only to be closed again at the end of June. In June, the laughing epidemic spread to Ramashenye girls’ middle school, near Bukoba, affecting 48 girls.

The school from which the epidemic sprang was sued; the children and parents transmitted it to the surrounding area. Other schools, Kashasha itself, and another village, comprising thousands of people, were all affected to some degree. Six to eighteen months after it started, the phenomenon died off. The following symptoms were reported on an equally massive scale as the reports of the laughter itself: pain, fainting, flatulence, respiratory problems, rashes, attacks of crying, and random screaming. In total 14 schools were shut down and 1000 people were affected.

Folie à deux (; ; French for "madness of two"), or shared psychosis, is a psychiatric syndrome in which symptoms of a delusional belief and sometimes hallucinations are transmitted from one individual to another. The same syndrome shared by more than two people may be called "folie à trois", "folie à quatre", "folie en famille" ("family madness"), or even "folie à plusieurs" ("madness of many").

Recent psychiatric classifications refer to the syndrome as shared psychotic disorder (DSM-IV – 297.3) and induced delusional disorder (F24) in the ICD-10, although the research literature largely uses the original name. This disorder is not in the current DSM (DSM-5). The disorder was first conceptualized in 19th-century French psychiatry by Charles Lasègue and Jean-Pierre Falret and is also known as Lasègue-Falret syndrome.

In psychiatry, derailment (also loosening of association, asyndesis, asyndetic thinking, knight's move thinking, or entgleisen) is a thought disorder characterized by discourse consisting of a sequence of unrelated or only remotely related ideas. The frame of reference often changes from one sentence to the next.

In a mild manifestation, this thought disorder is characterized by slippage of ideas further and further from the point of a discussion. Derailment can often be manifestly caused by intense emotions such as euphoria or hysteria. Some of the synonyms given above ("loosening of association", "asyndetic thinking") are used by some authors to refer just to a "loss of goal": discourse that sets off on a particular idea, wanders off and never returns to it. A related term is tangentiality—it refers to off-the-point, oblique or irrelevant answers given to questions. In some studies on creativity, "knight's move thinking", while it describes a similarly loose association of ideas, is not considered a mental disorder or the hallmark of one; it is sometimes used as a synonym for lateral thinking.

The 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD) classifies the below syndromes as culture-specific disorders:

This syndrome is most commonly diagnosed when the two or more individuals concerned live in proximity and may be socially or physically isolated and have little interaction with other people. Various sub-classifications of "folie à deux" have been proposed to describe how the delusional belief comes to be held by more than one person :

- Folie imposée is where a dominant person (known as the 'primary', 'inducer' or 'principal') initially forms a delusional belief during a psychotic episode and imposes it on another person or persons (known as the 'secondary', 'acceptor' or 'associate') with the assumption that the secondary person might not have become deluded if left to his or her own devices. If the parties are admitted to hospital separately, then the delusions in the person with the induced beliefs usually resolve without the need of medication.

- Folie simultanée describes either the situation where two people considered to suffer independently from psychosis influence the content of each other's delusions so they become identical or strikingly similar, or one in which two people "morbidly predisposed" to delusional psychosis mutually trigger symptoms in each other.

Folie à deux and its more populous cousins are in many ways a psychiatric curiosity. The current Diagnostic and Statistical Manual of Mental Disorders states that a person cannot be diagnosed as being delusional if the belief in question is one "ordinarily accepted by other members of the person's culture or subculture" (see entry for delusion). It is not clear at what point a belief considered to be delusional escapes from the "folie à..." diagnostic category and becomes legitimate because of the number of people holding it. When a large number of people may come to believe obviously false and potentially distressing things based purely on hearsay, these beliefs are not considered to be clinical delusions by the psychiatric profession and are labelled instead as mass hysteria.

In Italy, a similar phenomenon was tarantism, in which the victims were said to have been poisoned by a tarantula or scorpion. Its earliest known outbreak was in the 13th century, and the only antidote known was to dance to particular music to separate the venom from the blood. It occurred only in the summer months. As with dancing mania, people would suddenly begin to dance, sometimes affected by a perceived bite or sting and were joined by others, who believed the venom from their own old bites was reactivated by the heat or the music. Dancers would perform a tarantella, accompanied by music which would eventually "cure" the victim, at least temporarily.

Some participated in further activities, such as tying themselves up with vines and whipping each other, pretending to sword fight, drinking large amounts of wine, and jumping into the sea. Some died if there was no music to accompany their dancing. Sufferers typically had symptoms resembling those of dancing mania, such as headaches, trembling, twitching and visions.

As with dancing mania, participants apparently did not like the color black, and women were reported to be most affected. Unlike dancing mania, tarantism was confined to Italy and southern Europe. It was common until the 17th century, but ended suddenly, with only very small outbreaks in Italy until as late as 1959.

A study of the phenomenon in 1959 by religious history professor Ernesto de Martino revealed that most cases of tarantism were probably unrelated to spider bites. Many participants admitted that they had not been bitten, but believed they were infected by someone who had been, or that they had simply touched a spider. The result was mass panic, with a "cure" that allowed people to behave in ways that were, normally, prohibited at the time. Despite their differences, tarantism and dancing mania are often considered synonymous.

The person's appearance, behavior, and history, along with a psychological evaluation, are usually sufficient to establish a diagnosis. There is no test to confirm this diagnosis. Because the criteria are subjective, some people may be wrongly diagnosed.