# Bizarre Psychiatric Disorders

- Link: https://thedarksideofhumanity.com/bizarre-psychiatric-disorders/
- Published: 2026-06-11T05:55:02-04:00
- Author: Mandi Martyr

The Dark Side of HumanityKillers. Cults. Crime. Clinical Atlas / Classification Before Sensation Rare & Misunderstood Disorders A searchable dossier of psychiatric, neurological, sleep-related, dissociative and culture-shaped phenomena that destabilize identity, memory, perception, agency and bodily reality. “Bizarre” is a media description, not a diagnostic category. This atlas separates formal diagnoses from neurological syndromes, delusional themes, sleep disorders, cultural concepts of distress and historical labels whose scientific status is limited or disputed. Open the 58 filesDraw a random fileOpen glossary The fractured mind atlasAn abstract profile divided into clinical domains with red evidence lines and cream labels.PERCEPTIONIDENTITYMEMORYNEUROLOGYCULTURESLEEP Original editorial diagram: diagnostic boundaries, not a brain scan. Clinical ethics noticeMental illness is not monstrosity, and unusual symptoms do not make a person dangerous. The atlas rejects “freak show” framing, retrospective internet diagnosis and the use of psychiatric labels as automatic explanations for crime. Atlas SnapshotThe numbers describe this editorial collection, not disease prevalence, dangerousness, or diagnostic certainty.Condition files58Every entry includes status, core disturbance, differential diagnosis, media caution and urgent red flags.Clinical domains8Perception, identity, delusion, memory, sleep, neurology, culture and historical labels.Status classes8Formal diagnosis is kept separate from syndrome, symptom, cultural concept and contested terminology.Diagnostic rule1Rule out urgent neurological, toxic, metabolic, medication and sleep causes before admiring the rarity. Classification BoundariesA famous name can describe a diagnosis, a symptom pattern, a neurological sign, a cultural idiom, or nothing more than a memorable headline.Formal diagnosisPublished criteriaRecognized in an active classification such as ICD-11, DSM-5-TR or a specialist sleep classification. Recognition does not guarantee a biomarker or one universal treatment.Syndrome or signPattern, not one diseaseA recurring cluster may arise from several causes. Alien hand, Capgras-type misidentification and musical hallucinosis describe phenomena that still require an underlying diagnosis.Cultural conceptMeaning shapes distressLocal idioms organize bodily sensations, fear, trauma and social suffering. They should be interpreted respectfully, not exoticized.Historical labelEvidence may be weakSome memorable terms were built by colonial observers, newspapers, fiction or isolated case reports and may not represent a coherent disorder.Forensic limitDiagnosis is not a verdictA diagnosis does not by itself establish incompetence, insanity, involuntariness, false memory, malingering, dangerousness or absence of responsibility.Safety firstSudden change is medicalNew hallucinations, speech change, weakness, confusion, seizure, fever, head injury or inability to eat and drink require urgent evaluation before psychiatric storytelling. Interactive Fracture MapSelect a domain to inspect what is disrupted and filter the dossier wall to the relevant files.PIDMSNCHSelected domainPerception + body mapThese files show that ownership, movement, scale, pain, vision and awareness are constructed by brain systems that can separate after injury or illness.Perception + body map: 8Identity + misidentification: 8Delusions + attachment: 7Memory + dissociation: 7Sleep + arousal: 5Neurological + somatic: 7Culture-shaped distress: 8Historical + contested labels: 8 How the Labels ChangedA brief history of how rare mental and neurological phenomena moved from folklore and asylum description toward differential diagnosis and modern classification.1800sNamed syndromes emerge from individual case descriptionsNeurologists and alienists linked memorable patients to names and literary metaphors. Many labels survived even when their original theories did not.1900–50Misidentification, fugue and body-ownership syndromes are separatedClinical observation clarified that recognition, memory, identity and agency can fail independently rather than as one undifferentiated “madness.”1950–90Brain lesions, sleep laboratories and neuropsychology change the mapStroke, epilepsy surgery, sensory loss and sleep recording showed that apparently supernatural symptoms could arise from specific networks and state transitions.1990–2013Culture-bound syndrome gives way to cultural formulationPsychiatry increasingly recognized that all distress is culturally interpreted. DSM-5 replaced the older “culture-bound syndrome” framing with broader cultural concepts of distress.2022+ICD-11 and DSM-5-TR refine categories while uncertainty remainsSome conditions gained clearer placement, such as body integrity dysphoria and olfactory reference disorder in ICD-11, while many famous syndromes remain symptoms, provisional constructs or historical names. The Dossier WallSearch by symptom, diagnosis, underlying cause or media term. Filter by domain and clinical status, then compare up to three files.Search all filesSort cardsDossier orderAlphabeticalClinical domainStatus classDomain filtersAll domains 58Perception + body map 8Identity + misidentification 8Delusions + attachment 7Memory + dissociation 7Sleep + arousal 5Neurological + somatic 7Culture-shaped distress 8Historical + contested labels 8Status filtersAll status classes 58Formal diagnosis 10Recognized clinical syndrome 3Neurological syndrome/sign 13Delusional theme/syndrome 9Sleep classification 5Cultural concept of distress 9Contested/popular label 8Historical formulation 1Showing 58 of 58 filesReset filters 01 Perception + body mapNeurological syndrome/sign Alien Hand Syndrome A limb performs complex movements without the person experiencing normal voluntary control. Core disturbanceAgency and motor intention become uncoupled. The hand may grasp, manipulate, interfere with the other hand, or respond automatically to nearby objects. Typical contextMost often described after stroke, callosal surgery, tumour, neurodegeneration, or frontal and parietal injury. Clinical boundariesMedia caution: This is not possession, hidden desire, or deliberate misconduct. The movements arise from disrupted brain networks for agency and inhibition.Differential: Focal seizures, dystonia, chorea, functional neurological symptoms, medication effects, and ordinary involuntary movements.Urgency: New sudden symptoms require emergency neurological assessment because stroke or another acute brain event may be involved. Open fileCompare 02 Perception + body mapFormal diagnosis Body Integrity Dysphoria A persistent mismatch exists between the physical body and the person’s experienced body configuration. Core disturbanceThe person may feel that a limb or physical capacity does not belong within the body they experience as correct, sometimes producing a desire for disability. Typical contextICD-11 recognizes body integrity dysphoria under disorders of bodily distress or bodily experience. It is not included as a standalone DSM-5-TR diagnosis. Clinical boundariesMedia caution: The distress is not a stunt or casual wish. Unsafe attempts to alter the body can be medically catastrophic.Differential: Psychosis, body dysmorphic disorder, gender incongruence, malingering, neurological neglect syndromes, obsessive-compulsive phenomena.Urgency: Immediate help is needed when a person is planning or attempting self-injury to create a disability. Open fileCompare 03 Perception + body mapNeurological syndrome/sign Somatoparaphrenia A person insists that a limb or one side of the body belongs to someone else. Core disturbanceBody ownership is disrupted, frequently after right-hemisphere injury and often alongside paralysis, neglect, and lack of awareness of disability. Typical contextThe belief can be elaborate: a patient may assign the limb to a relative, clinician, or stranger while remaining otherwise conversational. Clinical boundariesMedia caution: Argument rarely repairs the missing sense of ownership. The presentation reflects neurological damage, not stubbornness.Differential: Anosognosia, hemineglect, alien hand syndrome, psychosis, delirium, severe dementia.Urgency: Sudden onset after weakness, confusion, facial droop, or speech change is a stroke emergency. Open fileCompare 04 Perception + body mapRecognized clinical syndrome Alice in Wonderland Syndrome Size, distance, body shape, time, or movement may feel radically distorted. Core disturbanceMicropsia, macropsia, altered body proportions, spatial distortion, and time distortion can occur while the person knows the experience is abnormal. Typical contextReported with migraine, epilepsy, infections, medications, sleep transitions, and other neurological states; children and adolescents are often represented in case literature. Clinical boundariesMedia caution: The literary name can trivialize an experience that is frightening and disorienting.Differential: Migraine aura, seizures, intoxication, psychosis, retinal disease, delirium, panic and dissociation.Urgency: New persistent distortions with severe headache, fever, weakness, seizure, or altered consciousness require urgent medical evaluation. Open fileCompare 05 Perception + body mapNeurological syndrome/sign Anosognosia A person cannot recognize or fully understand a serious illness or disability they demonstrably have. Core disturbanceThis is impaired self-awareness produced by brain dysfunction, not ordinary denial. A person with paralysis may sincerely insist that movement is intact. Typical contextCommonly discussed after stroke and in dementia, traumatic brain injury, psychotic illness, and other neurological conditions. Clinical boundariesMedia caution: Calling it “refusal to accept reality” mistakes a damaged awareness system for a moral choice.Differential: Psychological denial, delirium, aphasia, memory loss, low health literacy, malingering.Urgency: Sudden loss of insight alongside neurological symptoms requires emergency assessment. Open fileCompare 06 Perception + body mapNeurological syndrome/sign Pain Asymbolia Pain is detected but loses its normal emotional alarm and protective meaning. Core disturbanceA person may identify a stimulus as painful yet show little distress, withdrawal, or concern, creating a dangerous separation between sensation and aversion. Typical contextAssociated with lesions involving the insula, parietal operculum, and connected networks. Clinical boundariesMedia caution: The person is not necessarily “immune to pain.” The threat value of pain is altered, increasing injury risk.Differential: Peripheral neuropathy, congenital insensitivity to pain, dissociation, intoxication, factitious presentation.Urgency: Unrecognized burns, fractures, infection, and internal injury require prompt medical assessment. Open fileCompare 07 Perception + body mapNeurological syndrome/sign Akinetopsia Movement is no longer perceived as smooth motion and may appear as disconnected still frames. Core disturbanceMotion vision becomes impaired while colour, shape, and object recognition may remain partly intact. Typical contextRarely reported after bilateral damage to motion-processing regions, with some transient medication- or migraine-related presentations described. Clinical boundariesMedia caution: Crossing a street, pouring liquid, or following moving objects can become hazardous.Differential: Visual field loss, ocular disease, migraine aura, seizure, intoxication, functional visual symptoms.Urgency: Sudden visual change warrants urgent neurological and ophthalmologic evaluation. Open fileCompare 08 Perception + body mapNeurological syndrome/sign Palinopsia Images persist or recur after the original object has disappeared. Core disturbanceVisual afterimages may be vivid, prolonged, repeated, or displaced, reflecting disturbance in visual processing rather than an ordinary brief afterimage. Typical contextReported with migraine, seizures, posterior cortical lesions, medications, hallucinogen persisting perception disorder, and other neurological conditions. Clinical boundariesMedia caution: The symptom is not automatically psychiatric. A careful medication, toxicology, ophthalmology, and neurological review is essential.Differential: Normal afterimages, retinal disease, visual snow syndrome, migraine aura, psychosis, substance effects.Urgency: New palinopsia with headache, weakness, confusion, or seizures requires urgent assessment. Open fileCompare 09 Identity + misidentificationDelusional theme/syndrome Capgras Delusion A familiar person is believed to have been replaced by an identical impostor. Core disturbanceRecognition appears visually intact, but the expected feeling of familiarity is absent or interpreted through a delusional explanation. Typical contextSeen in psychotic disorders, dementia, epilepsy, brain injury, and other neuropsychiatric conditions. Clinical boundariesMedia caution: Confrontation can intensify fear. Risk assessment matters when the supposed “impostor” is viewed as dangerous.Differential: Prosopagnosia, delirium, dementia, PTSD-related hypervigilance, ordinary mistrust, malingering.Urgency: Urgent care is needed when threats, weapons, severe agitation, inability to care for self, or rapid neurological decline are present. Open fileCompare 10 Identity + misidentificationDelusional theme/syndrome Fregoli Delusion Different people are believed to be one familiar person repeatedly changing disguise. Core disturbanceFacial recognition, familiarity, and threat interpretation combine into a fixed false identification. Typical contextReported with schizophrenia-spectrum illness, brain injury, dementia, mood episodes, and other neurological disorders. Clinical boundariesMedia caution: The theatrical name can obscure the fear and surveillance themes that often drive the belief.Differential: Capgras delusion, persecutory delusion, prosopagnosia, delirium, trauma-related threat misreading.Urgency: Escalating pursuit, confrontation, or defensive violence requires immediate risk intervention. Open fileCompare 11 Identity + misidentificationDelusional theme/syndrome Intermetamorphosis Delusion People are believed to exchange identities, personalities, and appearances with one another. Core disturbanceThe person may insist that both the physical and psychological identity of familiar people has transformed. Typical contextA rare delusional misidentification phenomenon described in psychosis, dementia, and neurological illness. Clinical boundariesMedia caution: Retrospective internet descriptions often oversimplify complex cases into a single dramatic sentence.Differential: Fregoli, Capgras, delirium, dementia, dissociation, ordinary resemblance errors.Urgency: Safety planning is required when a misidentified person is feared, confronted, confined, or attacked. Open fileCompare 12 Identity + misidentificationDelusional theme/syndrome Syndrome of Subjective Doubles A person believes that one or more doubles of the self exist independently. Core disturbanceThe double may be assigned a separate life, location, personality, or responsibility for actions. Typical contextDescribed as a delusional misidentification syndrome in psychotic and neurological conditions. Clinical boundariesMedia caution: This is not the same as dissociative identity disorder, imaginative role-play, or an ordinary metaphorical “other self.”Differential: Autoscopic hallucination, heautoscopy, dissociative disorders, identity theft fears, malingering.Urgency: Urgent evaluation is needed when the double is linked to commands, self-harm, violence, or major self-neglect. Open fileCompare 13 Identity + misidentificationNeurological syndrome/sign Mirrored-Self Misidentification The reflection in a mirror is believed to be another person rather than the self. Core disturbanceVisual self-recognition fails despite the reflection moving in synchrony with the observer. Typical contextMost often reported in dementia and other neurological disorders affecting recognition and belief evaluation. Clinical boundariesMedia caution: Covering mirrors may reduce immediate distress, but the underlying neurological condition still requires assessment.Differential: Prosopagnosia, visual impairment, delirium, Capgras phenomenon, psychosis.Urgency: Rapid onset with confusion or focal neurological symptoms requires urgent medical investigation. Open fileCompare 14 Identity + misidentificationNeurological syndrome/sign Reduplicative Paramnesia A familiar place is believed to exist in duplicate or to have been relocated. Core disturbanceMemory, navigation, familiarity, and belief evaluation separate, producing a fixed conviction that two identical places exist. Typical contextAssociated with frontal and right-hemisphere injury, stroke, dementia, and traumatic brain injury. Clinical boundariesMedia caution: The person may appear oriented in conversation while holding a highly specific geographical misidentification.Differential: Delirium, ordinary disorientation, confabulation, dementia, psychosis.Urgency: New onset after injury or with other neurological signs requires urgent assessment. Open fileCompare 15 Identity + misidentificationDelusional theme/syndrome Cotard Syndrome The person believes they are dead, do not exist, are empty, or have lost organs or blood. Core disturbanceNihilistic delusions attack the sense of existence and bodily reality. Some people believe the world itself has ended. Typical contextMost often reported with severe depression, psychosis, bipolar disorder, neurological disease, and catatonia. Clinical boundariesMedia caution: Risk can be extreme because a person who believes they are already dead may stop eating, drinking, taking medication, or protecting themselves.Differential: Severe depression, delirium, depersonalization, dementia, psychosis, malingering.Urgency: This presentation requires urgent psychiatric and medical assessment, particularly with refusal of food or fluids, suicidality, or immobility. Open fileCompare 16 Identity + misidentificationDelusional theme/syndrome Clinical Lycanthropy A person believes they are transforming into, have become, or behave as an animal. Core disturbanceThe delusion may involve a wolf but can involve many species; “clinical zoanthropy” is the broader term. Typical contextReported in psychotic disorders, severe mood episodes, substance states, epilepsy, and culture-shaped belief systems. Clinical boundariesMedia caution: Folklore and horror language should not replace assessment of psychosis, mood, substances, and neurological disease.Differential: Species dysphoria claims, role-play, culturally sanctioned ritual, intoxication, dissociation.Urgency: Urgent care is needed when the person cannot eat, sleep, remain safe, or is acting on dangerous commands or fears. Open fileCompare 17 Delusions + attachmentDelusional theme/syndrome Erotomania A person believes another individual is secretly in love with them despite contrary evidence. Core disturbanceCoincidence, silence, public gestures, media posts, and rejection may be reinterpreted as coded proof of hidden love. Typical contextClassically described as de Clerambault syndrome and often considered within delusional disorder, erotomanic type. Clinical boundariesMedia caution: Fandom and admiration are not disorders. Clinical concern begins with fixed delusion, impairment, repeated unwanted contact, or risk.Differential: Ordinary infatuation, stalking without delusion, mania, personality pathology, obsessive-compulsive phenomena.Urgency: Threats, escalating pursuit, forced entry, weapons, suicidal crisis, or retaliatory anger require immediate intervention. Open fileCompare 18 Delusions + attachmentDelusional theme/syndrome Othello Syndrome A partner is believed to be unfaithful despite absent or contradictory evidence. Core disturbanceNeutral events become proof of betrayal, driving interrogation, surveillance, checking, and coercive control. Typical contextSeen with delusional disorder, alcohol and stimulant misuse, dementia, Parkinsonian disorders, brain injury, and psychosis. Clinical boundariesMedia caution: This syndrome has a clearer association with interpersonal danger than many rare conditions; partner safety must not be subordinated to diagnostic fascination.Differential: Actual infidelity, coercive control without delusion, OCD jealousy, trauma, personality pathology, substance intoxication.Urgency: Immediate safety planning is necessary when threats, stalking, confinement, assault, or access to weapons are present. Open fileCompare 19 Delusions + attachmentRecognized clinical syndrome Folie à Deux / Shared Delusional Beliefs Closely connected people come to share or reinforce a fixed delusional system. Core disturbanceThe older “primary imposes, secondary adopts” model is useful but often too simple; some relationships show mutual construction, dependence, isolation, and coercion. Typical contextModern classification usually records the individual psychotic or delusional disorders rather than treating shared psychosis as one uniform standalone entity. Clinical boundariesMedia caution: Agreement, conspiracy belief, cult membership, coercive control, and shared psychosis are not interchangeable.Differential: Independent psychotic disorders, misinformation, coercive persuasion, malingering, culturally shared belief, folie en famille.Urgency: Separation and urgent evaluation may be required when the shared belief drives neglect, barricading, suicide, violence, or harm to children. Open fileCompare 20 Delusions + attachmentDelusional theme/syndrome Delusional Infestation A person is convinced that parasites, fibres, organisms, or foreign material infest the body or environment. Core disturbanceSkin sensations and ordinary debris are interpreted as evidence; repeated cleaning, picking, specimen collection, and pesticide use may follow. Typical contextCan occur as a primary delusional disorder or secondary to substances, neurological disease, medication effects, or medical illness. Clinical boundariesMedia caution: Real infestation and dermatologic disease must be investigated before a delusional explanation is accepted.Differential: Scabies, lice, neuropathy, medication effects, stimulant use, dermatitis, OCD, somatic symptom disorder.Urgency: Urgent care is needed for poisoning, severe skin damage, infection, eye injury, or danger to children and pets from chemicals. Open fileCompare 21 Delusions + attachmentFormal diagnosis Olfactory Reference Disorder A person is preoccupied with the belief that they emit an offensive body odour that others notice. Core disturbanceOrdinary gestures such as coughing, opening a window, or touching the nose may be interpreted as confirmation. Typical contextICD-11 recognizes olfactory reference disorder within obsessive-compulsive and related disorders; insight can range from good to absent. Clinical boundariesMedia caution: The suffering can be severe, producing social withdrawal, excessive washing, reassurance seeking, and suicidality.Differential: Actual medical odour, body dysmorphic disorder, social anxiety, OCD, depression, psychosis.Urgency: Urgent help is needed with suicidal thoughts, severe self-neglect, dangerous cleaning practices, or complete social withdrawal. Open fileCompare 22 Delusions + attachmentContested/popular label “Truman Show” Delusion The person believes their life is secretly staged, filmed, broadcast, or populated by actors. Core disturbanceThis is a modern descriptive theme for persecutory or referential delusions, not a separate formal diagnosis. Typical contextTechnology and popular culture supply the imagery through which psychosis may be expressed. Clinical boundariesMedia caution: The label can be memorable but should never substitute for diagnosing the underlying psychotic, mood, substance-related, or neurological condition.Differential: Actual surveillance, stalking, online harassment, mania, substance-induced psychosis, trauma-related hypervigilance.Urgency: Urgent care is needed when the belief drives escape attempts, confrontation, self-harm, or violence against supposed actors. Open fileCompare 23 Delusions + attachmentFormal diagnosis Somatic-Type Delusional Disorder A fixed false belief centres on bodily function, disease, deformity, contamination, or internal change. Core disturbanceThe conviction persists despite appropriate evaluation and is not better explained by another disorder or a genuine medical condition. Typical contextThemes may involve infection, malformed organs, altered appearance, internal blockage, or bodily deterioration. Clinical boundariesMedia caution: Clinicians must avoid diagnostic overshadowing: rare disease and delusion can coexist.Differential: Somatic symptom disorder, illness anxiety, body dysmorphic disorder, neurological disease, real medical illness.Urgency: Medical instability, dangerous self-treatment, surgery seeking, poisoning, or suicidality requires immediate intervention. Open fileCompare 24 Memory + dissociationFormal diagnosis Dissociative Amnesia Important autobiographical information becomes inaccessible beyond ordinary forgetting. Core disturbanceMemory loss often concerns trauma or severe stress and may be localized, selective, generalized, or systematized. Typical contextThe diagnosis requires exclusion of neurological disease, substances, sleep disorders, ordinary forgetting, and deliberate feigning. Clinical boundariesMedia caution: Amnesia neither proves truth nor proves deception. Forensic memory claims require careful corroboration.Differential: Traumatic brain injury, epilepsy, dementia, intoxication, PTSD, malingering, sleep deprivation.Urgency: New amnesia with head injury, seizure, weakness, fever, or intoxication is a medical emergency. Open fileCompare 25 Memory + dissociationFormal diagnosis Dissociative Fugue A person travels or wanders while unable to recall key autobiographical information. Core disturbanceFugue is generally treated as a feature of dissociative amnesia rather than a separate diagnosis. Typical contextIdentity confusion or adoption of a new identity can occur, but dramatic complete reinvention is less typical than fiction suggests. Clinical boundariesMedia caution: Missing-person investigations must remain open to crime, injury, exploitation, substance use, and neurological illness.Differential: Dementia, delirium, epilepsy, intoxication, trafficking, head injury, malingering.Urgency: Any unidentified or wandering person with memory loss needs immediate medical and safeguarding assessment. Open fileCompare 26 Memory + dissociationFormal diagnosis Depersonalization / Derealization Disorder The self or world feels unreal, distant, dreamlike, artificial, or detached. Core disturbanceReality testing remains intact: the person usually knows the feeling is a disturbance rather than literal proof that the world is fake. Typical contextEpisodes may follow panic, trauma, severe stress, sleep deprivation, substances, migraine, or occur as a persistent disorder. Clinical boundariesMedia caution: It is not the same as psychosis, although the subjective experience can be terrifying.Differential: Psychosis, epilepsy, migraine aura, substance effects, PTSD, panic disorder, vestibular illness.Urgency: Urgent evaluation is needed with new neurological signs, intoxication, inability to function, or suicidal despair. Open fileCompare 27 Memory + dissociationContested/popular label Ganser Syndrome A person gives strikingly approximate answers and may show confusion, amnesia, hallucinations, or altered consciousness. Core disturbanceHistorically called “prison psychosis,” Ganser syndrome has been interpreted as dissociative, psychotic, neurological, factitious, or malingering across different cases. Typical contextThe classic example is answering near the correct response rather than randomly: for example, saying three when asked two plus two. Clinical boundariesMedia caution: The label is controversial and should never be used as shorthand for deception.Differential: Delirium, intellectual disability, psychosis, neurological disease, dissociation, malingering, factitious disorder.Urgency: Acute confusion or fluctuating consciousness is a medical emergency until delirium and neurological causes are excluded. Open fileCompare 28 Memory + dissociationNeurological syndrome/sign Confabulation Memory gaps are filled with inaccurate accounts that the person does not consciously intend to fabricate. Core disturbanceThe stories may be plausible or fantastical and can change as the brain attempts to maintain continuity. Typical contextAssociated with Korsakoff syndrome, frontal injury, dementia, aneurysm, stroke, and other neurocognitive disorders. Clinical boundariesMedia caution: Confabulation is not lying. Confidence and detail do not establish accuracy.Differential: Ordinary memory error, delusion, false confession, suggestibility, malingering, dementia.Urgency: New confabulation with confusion, gait change, malnutrition, or heavy alcohol use requires urgent assessment and thiamine consideration. Open fileCompare 29 Memory + dissociationNeurological syndrome/sign Korsakoff Syndrome Severe persistent memory impairment follows thiamine deficiency and injury to memory circuits. Core disturbancePeople may have profound difficulty forming new memories, variable loss of older memories, apathy, and confabulation. Typical contextOften associated with alcohol dependence but can arise from any severe prolonged thiamine deficiency. Clinical boundariesMedia caution: Moralizing alcohol use can delay recognition of a preventable and potentially fatal nutritional emergency.Differential: Dementia, traumatic brain injury, delirium, depression, medication effects.Urgency: Suspected Wernicke encephalopathy (confusion, eye-movement abnormalities, gait instability) requires immediate parenteral thiamine. Open fileCompare 30 Memory + dissociationFormal diagnosis Dissociative Identity Disorder Discontinuities in identity occur with recurrent gaps in memory and a sense of disrupted agency. Core disturbanceThe disorder involves more than ordinary role shifts and is associated with significant distress or impairment. Typical contextIts presentation, prevalence, mechanisms, and relationship to trauma and suggestion remain actively debated, but the diagnosis is formally recognized. Clinical boundariesMedia caution: Media depictions commonly exaggerate violence, dramatic switching, and courtroom spectacle.Differential: PTSD, borderline personality disorder, psychotic disorders, epilepsy, substance use, culturally normative possession states, malingering.Urgency: Immediate help is needed with self-harm, suicidality, dangerous amnesia, exploitation, or inability to maintain basic safety. Open fileCompare 31 Sleep + arousalSleep classification Exploding Head Syndrome A sudden imagined crash, explosion, flash, or electrical sensation occurs during sleep-wake transition. Core disturbanceThe event is usually painless and brief but can trigger intense fear, palpitations, and insomnia. Typical contextClassified among parasomnias; stress, sleep disruption, and variable neurological excitability may contribute. Clinical boundariesMedia caution: Despite the dramatic name, it does not mean the head is injured or that a stroke has occurred.Differential: Nocturnal seizures, thunderclap headache, PTSD, panic, medication effects, environmental noise.Urgency: Seek urgent care for actual severe headache, weakness, loss of consciousness, seizure, or persistent neurological symptoms. Open fileCompare 32 Sleep + arousalSleep classification Kleine–Levin Syndrome Recurrent episodes of extreme sleepiness occur with cognitive and behavioural change. Core disturbanceDuring episodes, a person may sleep most of the day and experience confusion, derealization, altered appetite, irritability, or disinhibition. Typical contextEpisodes typically recur over years and are separated by periods of near-normal functioning. Clinical boundariesMedia caution: The “Sleeping Beauty” nickname minimizes disability and can sexualize or trivialize patients.Differential: Bipolar disorder, narcolepsy, epilepsy, encephalitis, substance use, depression, metabolic disease.Urgency: First episodes require medical evaluation to exclude encephalitis, toxic exposure, seizures, and other dangerous causes. Open fileCompare 33 Sleep + arousalSleep classification Sexsomnia Sexual behaviour occurs during sleep with absent or severely impaired conscious awareness. Core disturbanceSexsomnia is generally understood as an NREM disorder of arousal and may involve vocalization, touching, masturbation, initiation of sex, or rarely more complex behaviour. Typical contextSleep deprivation, alcohol, obstructive sleep apnea, stress, medications, and other parasomnias can increase arousal instability. Clinical boundariesMedia caution: A diagnosis does not create consent, erase partner harm, or automatically establish a legal defence.Differential: Wakeful behaviour, REM behaviour disorder, nocturnal epilepsy, substance intoxication, malingering, dissociative states.Urgency: Immediate safety planning is needed when behaviour is non-consensual, aggressive, involves children, or creates injury risk. Open fileCompare 34 Sleep + arousalSleep classification Recurrent Isolated Sleep Paralysis Awareness returns while voluntary movement remains temporarily blocked at sleep onset or awakening. Core disturbanceDream imagery can intrude into wakefulness, producing sensed presence, pressure, shadows, voices, or out-of-body sensations. Typical contextEpisodes are associated with irregular sleep, sleep deprivation, stress, narcolepsy, and sleeping supine. Clinical boundariesMedia caution: Cultural interpretations may include demons, spirits, or attacks; the physiological mechanism involves REM atonia persisting into awareness.Differential: Nocturnal seizures, panic, narcolepsy, PTSD, psychosis, respiratory events.Urgency: Assessment is important when episodes are frequent, injurious, accompanied by daytime sleep attacks, or suggest narcolepsy. Open fileCompare 35 Sleep + arousalSleep classification REM Sleep Behaviour Disorder Dream-enactment behaviours occur because normal REM muscle paralysis is reduced or absent. Core disturbanceA person may shout, punch, kick, leap from bed, or strike a partner while acting out vivid dreams. Typical contextCan be medication-associated or idiopathic and may precede Parkinsonian neurodegenerative disease by years. Clinical boundariesMedia caution: This is not proof of violent character; it is a sleep motor-control disorder with substantial injury risk.Differential: NREM parasomnia, nocturnal epilepsy, sleep apnea arousals, PTSD nightmares, intoxication.Urgency: Prompt sleep and neurological evaluation is warranted, especially with injury or new movement, balance, smell, or cognitive changes. Open fileCompare 36 Neurological + somaticNeurological syndrome/sign Charles Bonnet Syndrome People with significant vision loss experience vivid visual hallucinations while often knowing they are not real. Core disturbanceImages may include patterns, people, animals, buildings, or scenes created by visual brain activity in the absence of normal input. Typical contextAssociated with macular degeneration, glaucoma, diabetic eye disease, and other causes of visual impairment. Clinical boundariesMedia caution: Patients may hide symptoms for fear of being labelled psychotic. Reassurance and vision assessment are essential.Differential: Delirium, dementia, medication effects, seizures, psychosis, migraine aura.Urgency: New hallucinations with confusion, fever, neurological signs, or loss of insight require urgent medical evaluation. Open fileCompare 37 Neurological + somaticRecognized clinical syndrome Musical Hallucinosis Music is heard without an external source, often as familiar songs, hymns, or repeated fragments. Core disturbanceThe experience can arise from hearing loss, neurological disease, epilepsy, medications, psychiatric illness, or sensory deprivation. Typical contextMany people retain insight and recognize that the music is internally generated. Clinical boundariesMedia caution: It is not automatically psychosis and should trigger hearing, medication, and neurological review.Differential: Tinnitus, environmental sound, temporal-lobe seizures, psychosis, delirium, obsessive imagery.Urgency: Sudden onset with confusion, seizure, weakness, or medication toxicity requires urgent assessment. Open fileCompare 38 Neurological + somaticNeurological syndrome/sign Foreign Accent Syndrome Speech changes after brain or functional disturbance and is perceived by listeners as a foreign accent. Core disturbanceAltered timing, stress, vowel production, articulation, and prosody create the impression of an accent not intentionally adopted. Typical contextMost often reported after stroke or head injury; migraine, multiple sclerosis, tumour, and functional neurological presentations also occur. Clinical boundariesMedia caution: The person has not acquired a new language or invented a persona.Differential: Dysarthria, apraxia of speech, mania, psychosis, deliberate accent adoption, medication effects.Urgency: Sudden speech change is a stroke emergency until proven otherwise. Open fileCompare 39 Neurological + somaticNeurological syndrome/sign Stiff-Person Syndrome Progressive stiffness and painful spasms are triggered by sound, touch, stress, or unexpected movement. Core disturbanceA rare autoimmune neurological spectrum affects inhibitory signalling, posture, gait, and startle responses. Typical contextSome cases are associated with GAD antibodies, cancer-related antibodies, diabetes, and other autoimmune disease. Clinical boundariesMedia caution: Stress can trigger spasms, but the condition is not “just anxiety.”Differential: Dystonia, spasticity, Parkinsonism, functional neurological disorder, tetanus, medication effects.Urgency: Falls, breathing difficulty, severe spasms, autonomic instability, or rapid progression require urgent care. Open fileCompare 40 Neurological + somaticFormal diagnosis Tourette Syndrome Multiple motor tics and at least one vocal tic occur over time, typically beginning in childhood. Core disturbanceTics wax and wane, can be briefly suppressed, and are often preceded by uncomfortable sensory urges. Typical contextADHD, obsessive-compulsive symptoms, anxiety, sleep problems, and learning difficulties may coexist. Clinical boundariesMedia caution: Coprolalia affects a minority. Reducing Tourette syndrome to involuntary swearing is inaccurate and stigmatizing.Differential: Stereotypies, seizures, dystonia, medication-induced movements, functional tic-like behaviours.Urgency: Urgent care is needed for severe self-injurious tics, sudden explosive onset with other neurological symptoms, or medication reactions. Open fileCompare 41 Neurological + somaticFormal diagnosis Pica Non-food substances are persistently eaten despite medical risk. Core disturbanceThe behaviour must be developmentally inappropriate and not part of a culturally supported practice. Typical contextAssociated with iron or zinc deficiency, pregnancy, developmental disability, autism, stress, poverty, and other medical or psychiatric contexts. Clinical boundariesMedia caution: The urgent issue is not shock value but poisoning, obstruction, infection, dental damage, and nutritional deficiency.Differential: Culturally sanctioned ingestion, food insecurity, obsessive-compulsive behaviour, psychosis, developmental exploration.Urgency: Immediate medical care is needed after ingestion of lead, batteries, sharp objects, chemicals, magnets, or substances causing obstruction. Open fileCompare 42 Neurological + somaticFormal diagnosis Functional Neurological Disorder Genuine neurological symptoms occur through altered nervous-system functioning rather than structural damage visible on routine tests. Core disturbanceSymptoms may include weakness, tremor, seizures, gait change, sensory loss, speech disturbance, or movement abnormalities. Typical contextDiagnosis is made through positive clinical signs, not merely because tests are normal or symptoms are unusual. Clinical boundariesMedia caution: “Functional” does not mean fake, voluntary, or imagined. Malingering is a separate determination.Differential: Epilepsy, stroke, multiple sclerosis, movement disorders, medication effects, factitious disorder.Urgency: First seizures, new weakness, speech loss, severe headache, or injury still require emergency assessment. Open fileCompare 43 Culture-shaped distressCultural concept of distress Koro / Genital Retraction Anxiety A person fears that the genitals are retracting into the body and may disappear or cause death. Core disturbancePanic, bodily vigilance, sexual guilt, cultural beliefs, and social contagion can shape individual or outbreak presentations. Typical contextHistorically described in parts of Asia but reported across cultures with different explanatory models. Clinical boundariesMedia caution: Exotic framing distorts the condition. The fear is real even when the bodily interpretation is mistaken.Differential: Panic disorder, body dysmorphic disorder, genital medical disease, psychosis, substance effects.Urgency: Injury from clamps, pulling, binding, chemicals, or self-surgery requires immediate medical care. Open fileCompare 44 Culture-shaped distressCultural concept of distress Taijin Kyofusho Social fear centres on offending, embarrassing, or harming others through one’s appearance, gaze, odour, or behaviour. Core disturbanceThe distress is relational: the feared consequence is often that other people will be made uncomfortable. Typical contextBest known in Japanese psychiatry, with overlapping but non-identical relationships to social anxiety and olfactory reference concerns. Clinical boundariesMedia caution: It should not be reduced to a national stereotype or treated as simply “Japanese social anxiety.”Differential: Social anxiety disorder, olfactory reference disorder, body dysmorphic disorder, psychosis, OCD.Urgency: Urgent support is needed with severe isolation, malnutrition, suicidality, or inability to leave home. Open fileCompare 45 Culture-shaped distressCultural concept of distress Dhat Syndrome Distress is attributed to semen loss, often with fatigue, weakness, anxiety, and sexual symptoms. Core disturbanceCultural beliefs about semen as a vital substance shape symptom meaning and help-seeking. Typical contextDescribed most often in South Asian clinical literature, though semen-loss anxiety occurs in multiple settings. Clinical boundariesMedia caution: A respectful assessment should address sexual health, depression, anxiety, misinformation, and medical symptoms without ridicule.Differential: Depression, anxiety, sexual dysfunction, urinary disease, somatic symptom disorder, culturally shaped health anxiety.Urgency: Urgent care is needed with suicidality, severe depression, genital injury, or untreated infection. Open fileCompare 46 Culture-shaped distressCultural concept of distress Ataque de Nervios An intense crisis may involve screaming, crying, trembling, aggression, fainting, dissociation, or a sense of losing control. Core disturbanceThe episode often follows family conflict, bereavement, trauma, or a shocking event and may be culturally intelligible rather than evidence of one specific disorder. Typical contextCommonly described in Latin American and Caribbean communities, with wide variation in symptoms and severity. Clinical boundariesMedia caution: Translation into “panic attack” alone may erase grief, family context, trauma, and cultural meaning.Differential: Panic attack, dissociation, PTSD, seizure, intoxication, delirium, acute stress reaction.Urgency: Medical assessment is needed with collapse, injury, seizure-like activity, pregnancy complications, or persistent altered consciousness. Open fileCompare 47 Culture-shaped distressCultural concept of distress Khyâl Cap / Wind Attacks Bodily sensations are feared as dangerous movement of wind-like energy through the body. Core disturbanceDizziness, palpitations, neck soreness, tinnitus, breathlessness, and catastrophic fear may form a culturally coherent panic syndrome. Typical contextDescribed in Cambodian communities, particularly in relation to trauma and refugee experience. Clinical boundariesMedia caution: Treating the experience as generic panic can miss trauma history, idiom, and culturally meaningful bodily explanations.Differential: Panic disorder, cardiac disease, vestibular illness, PTSD, medication effects, anemia.Urgency: Chest pain, fainting, neurological deficits, or severe breathing difficulty require emergency evaluation. Open fileCompare 48 Culture-shaped distressCultural concept of distress Kufungisisa / “Thinking Too Much” Emotional and bodily distress is described through excessive thinking, worry, and mental burden. Core disturbanceThe Shona idiom can connect rumination with headaches, fatigue, anxiety, depression, family strain, poverty, and social adversity. Typical contextIt functions as a meaningful explanatory model rather than a one-to-one substitute for a Western diagnosis. Clinical boundariesMedia caution: Good assessment asks what “thinking too much” means to the individual and community.Differential: Depression, generalized anxiety, trauma, grief, insomnia, medical illness.Urgency: Urgent help is needed with suicidality, psychosis, inability to eat or sleep, or severe functional collapse. Open fileCompare 49 Culture-shaped distressCultural concept of distress Susto Illness and distress are attributed to a frightening event that causes the soul or vital essence to leave or become disrupted. Core disturbanceSymptoms may include sleep disturbance, sadness, appetite loss, weakness, bodily pain, and social withdrawal. Typical contextDescribed across Latin American communities with local variation in beliefs, rituals, and healing practices. Clinical boundariesMedia caution: Respecting the explanatory model does not prevent simultaneous medical and psychiatric assessment.Differential: PTSD, depression, grief, anxiety, infection, anemia, endocrine disease.Urgency: Severe dehydration, malnutrition, suicidality, or untreated medical disease requires immediate care. Open fileCompare 50 Culture-shaped distressCultural concept of distress Latah An exaggerated startle response may be followed by automatic imitation, obedience, gestures, or speech. Core disturbanceThe behaviour is shaped by neurophysiology, social expectation, interpersonal context, and local cultural interpretation. Typical contextHistorically described in Malaysia and Indonesia, with related startle syndromes reported elsewhere. Clinical boundariesMedia caution: Colonial descriptions often treated affected people as entertainment. Modern discussion must reject reenactment and humiliation.Differential: Tourette syndrome, epilepsy, functional neurological symptoms, PTSD hyperarousal, ordinary startle.Urgency: Injury, exploitation, restraint, or sudden neurological change requires clinical assessment. Open fileCompare 51 Historical + contested labelsContested/popular label Paris Syndrome Severe distress is attributed to the collapse of idealized expectations during travel in Paris. Core disturbanceReports describe anxiety, derealization, confusion, autonomic symptoms, and occasionally psychosis in overwhelmed travellers. Typical contextThe term is media-amplified and not a standard diagnosis; culture shock, exhaustion, language barriers, and pre-existing illness may be more useful explanations. Clinical boundariesMedia caution: The label is often presented as an exotic Japanese phenomenon despite weak epidemiological evidence.Differential: Culture shock, panic, psychosis, jet lag, substance use, medical illness.Urgency: Acute confusion, psychosis, suicidal behaviour, or medical instability requires emergency care regardless of the travel label. Open fileCompare 52 Historical + contested labelsContested/popular label Jerusalem Syndrome Religious preoccupation or psychosis becomes dramatically focused on Jerusalem and biblical identity. Core disturbanceSome travellers develop preaching, ritual purification, wandering, grandiose identity, or apocalyptic beliefs. Typical contextMost cases involve pre-existing psychiatric vulnerability; a pure location-caused syndrome remains controversial. Clinical boundariesMedia caution: Religious devotion is not pathology. Impairment, delusion, danger, and loss of reality testing define clinical concern.Differential: Mania, schizophrenia-spectrum illness, substance use, pilgrimage behaviour, culturally sanctioned religious practice.Urgency: Urgent assessment is needed with exposure, dehydration, aggression, dangerous wandering, or inability to care for self. Open fileCompare 53 Historical + contested labelsContested/popular label Stendhal Syndrome Art exposure is said to provoke dizziness, panic, dissociation, faintness, or overwhelming emotion. Core disturbanceThe label is associated with intense aesthetic experience, fatigue, travel stress, heat, crowds, and expectation. Typical contextIt is not a standard diagnosis and evidence for a distinct syndrome is limited. Clinical boundariesMedia caution: A memorable name should not obscure cardiac, neurological, metabolic, panic, or medication-related causes of collapse.Differential: Panic attack, vasovagal syncope, dehydration, arrhythmia, migraine, seizure.Urgency: Loss of consciousness, chest pain, severe headache, or neurological symptoms require emergency care. Open fileCompare 54 Historical + contested labelsContested/popular label “Renfield Syndrome” / Clinical Vampirism A sensational label is applied to compulsive or ritualized interest in consuming blood. Core disturbanceThe term is not a formal diagnosis and reported cases may involve psychosis, paraphilic interest, self-harm, trauma, substance use, or symbolic ritual. Typical contextIts name comes from fiction, which makes it especially vulnerable to distortion in crime media. Clinical boundariesMedia caution: The label is not a substitute for describing actual behaviour, consent, medical risk, and the underlying condition.Differential: Psychosis, pica, paraphilic disorder, obsessive-compulsive symptoms, self-injury, culturally sanctioned ritual.Urgency: Blood exposure, poisoning, infection, coercion, assault, or self-harm requires immediate medical and safeguarding response. Open fileCompare 55 Historical + contested labelsContested/popular label Celebriphilia An intense attraction or fixation on celebrities is framed as a distinct condition. Core disturbanceThe word is descriptive and not a standard diagnosis. Clinically significant cases may instead involve erotomania, obsessive behaviour, mania, loneliness, or parasocial attachment. Typical contextMost celebrity interest is ordinary and harmless; impairment, delusion, boundary violation, or loss of control changes the clinical picture. Clinical boundariesMedia caution: Ordinary fandom is not a medical condition, and a novelty label can glamorize stalking.Differential: Erotomania, obsessive-compulsive disorder, mania, stalking without delusion, ordinary fandom.Urgency: Threats, repeated unwanted contact, forced entry, weapons, or suicidal crisis require immediate intervention. Open fileCompare 56 Historical + contested labelsContested/popular label Pibloktoq / “Arctic Hysteria” Historical reports described sudden agitation, stripping, running, shouting, imitation, seizure-like activity, and later amnesia. Core disturbanceThe category was produced largely through colonial observation and may have combined diverse medical, social, environmental, and interpretive phenomena. Typical contextModern scholars question whether it represents a coherent culture-bound syndrome at all. Clinical boundariesMedia caution: The term should be treated as a contested historical construction, not a reliable diagnosis of Inuit people.Differential: Seizure, hypothermia, intoxication, trauma, delirium, functional symptoms, observer bias.Urgency: Any sudden behavioural or neurological crisis in extreme cold requires emergency medical and environmental response. Open fileCompare 57 Historical + contested labelsHistorical formulation Glass Delusion A person believes the body is made of glass and may shatter from touch or movement. Core disturbanceThe belief appeared in European historical records, especially from the late medieval and early modern periods. Typical contextIt may reflect period-specific symbolism, melancholy, status, bodily vulnerability, and changing material culture. Clinical boundariesMedia caution: Retrospective diagnosis is uncertain; historical descriptions should not be forced into modern categories without context.Differential: Somatic delusion, severe depression, psychosis, culturally shaped metaphor, neurological disease.Urgency: In any modern presentation, immobility, starvation, self-neglect, or self-harm requires urgent assessment. Open fileCompare 58 Historical + contested labelsCultural concept of distress Amok A historical cultural label described a sudden violent outburst followed by exhaustion or amnesia. Core disturbanceColonial and psychiatric writing often treated “running amok” as an exotic syndrome, while modern cases require ordinary assessment of violence, psychosis, substances, trauma, and social context. Typical contextThe word entered global language and is now often used carelessly for mass violence. Clinical boundariesMedia caution: A cultural label must never be used to imply that violence is mysterious, inevitable, or ethnically characteristic.Differential: Psychosis, intoxication, mania, dissociation, planned violence, neurological illness, acute stress.Urgency: Any threat or active violence requires immediate emergency response and protection of potential victims. Open fileCompare No dossier matches those filters. Try a broader symptom or reset the atlas. Compare the FilesPlace up to three conditions side by side without implying that similar headlines have the same mechanism.Active fileChoose a dossierOpen any card to load the complete clinical boundary here. This atlas explains classification; it does not diagnose readers.Comparison trayClear trayNo files selected. Use “Compare” on any card. Forensic and True-Crime BoundariesRare symptoms become dangerous editorial material when a label is used to replace evidence.MythUnusual equals violentMost people with mental illness or neurological disease are not violent. Risk depends on the specific person, circumstances, substance use, victim access, threats, history and acute state, not the strangeness of a diagnosis.MythA diagnosis proves insanityLegal insanity, criminal responsibility, competence and involuntariness are jurisdiction-specific legal questions. A clinical name is only one piece of evidence.MythMemory loss erases evidenceAmnesia does not determine whether an act occurred or whether responsibility existed at the time. Independent records, behaviour, contemporaneous statements and physical evidence remain central.MythRare means impossible to fakeAny symptom can be misunderstood, exaggerated, induced, misreported or feigned. The answer is not cynical disbelief but structured assessment, collateral information and appropriate testing. Emergency Red FlagsThe rare label can wait. These signs require immediate professional assessment.Medical emergencySudden neurological changeNew weakness, facial droop, speech change, severe headache, seizure, fever, head injury, vision loss, confusion or inability to walk can indicate stroke, infection, toxicity or another emergency.Psychiatric emergencyImmediate danger or collapseSuicidal intent, threats, weapons, inability to eat or drink, severe agitation, catatonia, dangerous wandering, non-consensual behaviour, poisoning or inability to care for basic needs require urgent intervention. Sources and VerificationThe cards synthesize classification and clinical literature. They are not substitutes for diagnostic manuals, medical examination or specialist assessment.Verification sourceWorld Health Organization: ICD-11Current international classification browser for mental, behavioural, neurological and sleep disorders.Open source ↗Verification sourceAmerican Psychiatric Association: DSMOfficial DSM information and revision resources. Diagnostic criteria require licensed clinical use.Open source ↗Verification sourceNational Institute of Neurological Disorders and StrokePatient and professional information on neurological disease, including stiff-person spectrum and Tourette syndrome.Open source ↗Verification sourceNational Library of Medicine: PubMedSearchable biomedical literature for rare syndromes, case series, differential diagnosis and treatment evidence.Open source ↗Verification sourceNCBI BookshelfPeer-reviewed clinical overviews and medical reference chapters.Open source ↗Verification sourceWorld Health Organization: Mental HealthGlobal mental-health policy, classification and public-health guidance.Open source ↗Verification sourceNational Institute of Mental HealthResearch and public information on psychosis, mood, trauma, suicide prevention and psychiatric treatment.Open source ↗Verification sourceAmerican Academy of Sleep MedicineClinical sleep-medicine standards and the International Classification of Sleep Disorders.Open source ↗Verification sourceNational Academies: Forensic ScienceStandards-oriented reports relevant to expert evidence, reliability and courtroom claims.Open source ↗ The Dark Side of HumanityKillers. Cults. Crime. Evidence over spectacle, clinical boundaries over internet diagnosis, and human beings over sensational labels.This educational archive is not medical advice and should not be used to diagnose, confront or publicly label any person. Clinical GlossaryDifferential diagnosisThe structured process of considering and excluding other psychiatric, neurological, medical, toxic, sleep and social explanations.DelusionA fixed false belief held with strong conviction despite evidence, assessed within the person’s cultural and religious context.HallucinationA perception-like experience without a corresponding external stimulus. Hallucinations can arise from many psychiatric, neurological, sensory, sleep and substance-related causes.InsightThe degree to which a person recognizes that an experience or belief may result from illness or altered perception.ParasomniaAn unwanted behaviour or experience arising during sleep, sleep transitions or partial arousal.Cultural concept of distressA culturally meaningful way of experiencing, naming, explaining or communicating suffering. It is not a lesser or fictional form of distress.Diagnostic overshadowingThe error of attributing new medical symptoms to a psychiatric diagnosis without adequate investigation.Close glossary ConditionClose file Case file · FAQ Frequently asked questions What does this dossier cover? A searchable dossier of psychiatric, neurological, sleep-related, dissociative and culture-shaped phenomena that destabilize identity, memory, perception, agency and bodily reality. What is Capgras delusion? A familiar person is believed to have been replaced by an identical impostor. It is seen in psychotic disorders, dementia, epilepsy, brain injury and other neuropsychiatric conditions. What is Cotard syndrome? The person believes they are dead, do not exist, are empty, or have lost organs or blood. It is most often reported with severe depression, psychosis, bipolar disorder, neurological disease and catatonia. Does a diagnosis decide responsibility? No. A diagnosis does not by itself establish incompetence, insanity, involuntariness, false memory, malingering, dangerousness or absence of responsibility.