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.

Piblokto, also known as pibloktoq and Arctic hysteria, is a condition most commonly appearing in Inughuit (Greenlandic Inuit) societies living within the Arctic Circle. Piblokto is a culture-specific hysterical reaction in Inuit, especially women, who may perform irrational or dangerous acts, followed by amnesia for the event. Piblokto may be linked to repression of the personality of Inuit women. The condition appears most commonly in winter. It is considered to be a form of a culture-bound syndrome, although more recent studies (see "Skepticism" section) question whether it exists at all. Piblokto is also part of the glossary of cultural bound syndromes found in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV).

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.

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.

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.

Psychosexual conflicts, personality factors, and cultural beliefs are considered as being of etiological

significance to koro. Sexual adjustment histories of non-Chinese victims are often significant, such as premorbid sex inadequacy, sexual promiscuity, guilt over masturbation, and impotence.

Jones compiles the following symptoms based on their commonality in outbreaks occurring in 1980–1990:

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.

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.

"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.

When considering the biological mechanisms and evolutionary history of koro, it is important to look at it in the larger framework of mass hysteria. While the underlying mechanisms are still poorly understood, it has been suggested that the mirror neurons play a major role in mass hysteria outbreaks. Mirror neurons, which have been found in both human and non-human primates, are neurons that fire when one performs an action and when they observe another individual performing the same action. It is hypothesized that we evolved these mechanisms to learn from observation of others, as well as to facilitate imitation. However, within mirror neurons, there is some form of inhibitory process, which prevents us from blindly mimicking every action we observe others perform. New research into this area suggests that in mass hysteria outbreaks something goes amiss in this inhibitory process.

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.

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 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 outbreaks of dancing mania varied, and several characteristics of it have been recorded. Generally occurring in times of hardship, up to tens of thousands of people would appear to dance for hours, days, weeks, and even months.

Women have often been portrayed in modern literature as the usual participants in dancing mania, although contemporary sources suggest otherwise. Whether the dancing was spontaneous, or an organised event, is also debated. What is certain, however, is that dancers seemed to be in a state of unconsciousness, and unable to control themselves.

In his research into social phenomena, author Robert Bartholomew notes that contemporary sources record that participants often did not reside where the dancing took place. Such people would travel from place to place, and others would join them along the way. With them they brought customs and behaviour that were strange to the local people. Bartholomew describes how dancers wore "strange, colorful attire" and "held wooden sticks".

Robert Marks, in his study of hypnotism, notes that some decorated their hair with garlands. However, not all outbreaks involved foreigners, and not all were particularly calm. Bartholomew notes that some "paraded around naked" and made "obscene gestures". Some even had sexual intercourse. Others acted like animals, and jumped, hopped and leaped about.

They hardly stopped, and some danced until they broke their ribs and subsequently died. Throughout, dancers screamed, laughed, or cried, and some sang. Bartholomew also notes that observers of dancing mania were sometimes treated violently if they refused to join in. Participants demonstrated odd reactions to the colour red; in "A History of Madness in Sixteenth-Century Germany", Midelfort notes they "could not perceive the color red at all", and Bartholomew reports "it was said that dancers could not stand... the color red, often becoming violent on seeing [it]".

Bartholomew also notes that dancers "could not stand pointed shoes", and that dancers enjoyed their feet being hit. Throughout, those affected by dancing mania suffered from a variety of ailments, including chest pains, convulsions, hallucinations, hyperventilation, epileptic fits, and visions. In the end, most simply dropped down, overwhelmed with exhaustion. Midelfort, however, describes how some ended up in a state of ecstasy. Typically, the mania was contagious but it often struck small groups, such as families and individuals.

Islamophobia in the media refers to the occurrence or perception that media outlets tend to cover Muslims or Islam-related topics in a negative light. Islamophobia is defined as "Intense dislike or fear of Islam, esp. as a political force; hostility or prejudice towards Muslims".

DID is rarely diagnosed in children, despite the average age of appearance of the first alter being three years. This fact is cited as a reason to doubt the validity of DID, and proponents of both etiologies believe that the discovery of DID in a child that had never undergone treatment would critically undermine the SCM. Conversely, if children are found to only develop DID after undergoing treatment it would challenge the traumagenic model. , approximately 250 cases of DID in children have been identified, though the data does not offer unequivocal support for either theory. While children have been diagnosed with DID before therapy, several were presented to clinicians by parents who were themselves diagnosed with DID; others were influenced by the appearance of DID in popular culture or due to a diagnosis of psychosis due to hearing voices—a symptom also found in DID. No studies have looked for children with DID in the general population, and the single study that attempted to look for children with DID not already in therapy did so by examining siblings of those already in therapy for DID. An analysis of diagnosis of children reported in scientific publications, 44 case studies of single patients were found to be evenly distributed (i.e., each case study was reported by a different author) but in articles regarding groups of patients, four researchers were responsible for the majority of the reports.

The initial theoretical description of DID was that dissociative symptoms were a means of coping with extreme stress (particularly childhood sexual and physical abuse), but this belief has been challenged by the data of multiple research studies. Proponents of the traumagenic hypothesis claim the high correlation of child sexual and physical abuse reported by adults with DID corroborates the link between trauma and DID. However, the DID-maltreatment link has been questioned for several reasons. The studies reporting the links often rely on self-report rather than independent corroborations, and these results may be worsened by selection and referral bias. Most studies of trauma and dissociation are cross-sectional rather than longitudinal, which means researchers can not attribute causation, and studies avoiding recall bias have failed to corroborate such a causal link. In addition, studies rarely control for the many disorders comorbid with DID, or family maladjustment (which is itself highly correlated with DID). The popular association of DID with childhood abuse is relatively recent, occurring only after the publication of "Sybil" in 1973. Most previous examples of "multiples" such as Chris Costner Sizemore, whose life was depicted in the book and film "The Three Faces of Eve", disclosed no history of child abuse.

Rape trauma syndrome (RTS) is the psychological trauma experienced by a rape victim that includes disruptions to normal physical, emotional, cognitive, and interpersonal behavior. The theory was first described by psychiatrist Ann Wolbert Burgess and sociologist Lynda Lytle Holmstrom in 1974.

RTS is a cluster of psychological and physical signs, symptoms and reactions common to most rape victims immediately following and for months or years after a rape. While most research into RTS has focused on female victims, sexually abused males (whether by male or female perpetrators) also exhibit RTS symptoms. RTS paved the way for consideration of complex post-traumatic stress disorder, which can more accurately describe the consequences of serious, protracted trauma than posttraumatic stress disorder alone. The symptoms of RTS and post-traumatic stress syndrome overlap. As might be expected, a person who has been raped will generally experience high levels of distress immediately afterward. These feelings may subside over time for some people; however, individually each syndrome can have long devastating effects on rape victims and some victims will continue to experience some form of psychological distress for months or years. It has also been found that rape survivors are at high risk for developing substance use disorders, major depression, generalized anxiety disorder, obsessive-compulsive disorder, and eating disorders.

Little is known about prognosis of untreated DID. It rarely, if ever, goes away without treatment, but symptoms may resolve from time to time or wax and wane spontaneously. Patients with mainly dissociative and posttraumatic symptoms face a better prognosis than those with comorbid disorders or those still in contact with abusers, and the latter groups often face lengthier and more difficult treatment. Suicidal ideation, failed suicide attempts, and self-harm also occur. Duration of treatment can vary depending on patient goals, which can extend from elimination of all alters to merely reducing inter-alter amnesia, but generally takes years.

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.

Information on the frequency of conversion disorder in the West is limited, in part due to the complexities of the diagnostic process. In neurology clinics, the reported prevalence of unexplained symptoms among new patients is very high (between 30 and 60%). However, diagnosis of conversion typically requires an additional psychiatric evaluation, and since few patients will see a psychiatrist it is unclear what proportion of the unexplained symptoms are actually due to conversion. Large scale psychiatric registers in the US and Iceland found incidence rates of 22 and 11 newly diagnosed cases per 100,000 person-years, respectively. Some estimates claim that in the general population, between 0.011% and 0.5% of the population have conversion disorder.

Risk factors for mental illness include genetic inheritance, such as parents having depression, or a propensity for high neuroticism or "emotional instability".

In depression, parenting risk factors include parental unequal treatment, and there is association with high cannabis use.

In schizophrenia and psychosis, risk factors include migration and discrimination, childhood trauma, bereavement or separation in families, and abuse of drugs, including cannabis, and urbanicity.

In anxiety, risk factors may include family history (e.g. of anxiety), temperament and attitudes (e.g. pessimism), and parenting factors including parental rejection, lack of parental warmth, high hostility, harsh discipline, high maternal negative affect, anxious childrearing, modelling of dysfunctional and drug-abusing behaviour, and child abuse (emotional, physical and sexual).

Environmental events surrounding pregnancy and birth have also been implicated. Traumatic brain injury may increase the risk of developing certain mental disorders. There have been some tentative inconsistent links found to certain viral infections, to substance misuse, and to general physical health.

Social influences have been found to be important, including abuse, neglect, bullying, social stress, traumatic events and other negative or overwhelming life experiences. For bipolar disorder, stress (such as childhood adversity) is not a specific cause, but does place genetically and biologically vulnerable individuals at risk for a more severe course of illness. The specific risks and pathways to particular disorders are less clear, however. Aspects of the wider community have also been implicated, including employment problems, socioeconomic inequality, lack of social cohesion, problems linked to migration, and features of particular societies and cultures.

Socioeconomic status has also been looked at as a potential cause for personality disorders. There is a strong association with low parental/neighborhood socioeconomic status and personality disorder symptoms. In a recent study comparing parental socioeconomic status and a child's personality, it was seen that children who were from higher socioeconomic backgrounds were more altuistic, less risk seeking, and had overall higher IQs. These traits correlate with a low risk of developing personality disorders later on in life. In a study looking at female children who were detained for disciplinary actions found that psychological problems were most negatively associated with socioeconomic problems. Furthermore, social disorganization was found to be inversely correlated with personality disorder symptoms.

Child abuse and neglect consistently show up as risk factors to the development of personality disorders in adulthood. A study looked at retrospective reports of abuse of participants that had demonstrated psychopathology throughout their life and were later found to have past experience with abuse. In a study of 793 mothers and children, researchers asked mothers if they had screamed at their children, and told them that they did not love them or threatened to send them away. Children who had experienced such verbal abuse were three times as likely as other children (who did not experience such verbal abuse) to have borderline, narcissistic, obsessive-compulsive or paranoid personality disorders in adulthood. The sexually abused group demonstrated the most consistently elevated patterns of psychopathology. Officially verified physical abuse showed an extremely strong correlation with the development of antisocial and impulsive behavior. On the other hand, cases of abuse of the neglectful type that created childhood pathology were found to be subject to partial remission in adulthood.

Though some fears are inborn, the majority are learned. Phobias develop through negative experiences and through observation. One way children begin to develop fears is by witnessing or hearing about dangers. Ollendick proposes while some phobias may originate from a single traumatizing experience, others may be caused by simpler, or less dramatic, origins such as observing another child’s phobic reaction or through the exposure to media that introduces phobias.

- 2% of parents linked their child’s phobia to a [direct conditioning episode]

- 26% of parents linked their child’s phobia to a [vicarious conditioning episodes]

- 56% of parents linked their child’s phobia to their child’s very first contact with water

- 16% of parents could not directly link their child’s phobia

In addition to asking about the origins of a child’s fear, the questionnaire asked if parents believed that “information associated with adverse consequences was the most influential factor in the development of their child’s phobia.” The results were as followed:

- 0% of parents though it was the most influential factor

- 14% of parents though it was somewhat influential

- 86% of parents though it had little to no influence