Factitious Disorder Imposed on Another (Munchausen by proxy)

Updated: Jun 25, 2020
  • Author: Marc D Feldman, MD; Chief Editor: Glen L Xiong, MD  more...
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Practice Essentials

Factitious disorder imposed on another (FDIA; formerly known as factitious disorder by proxy and other similar names) has as its cardinal characteristic the production or feigning of physical or psychological symptoms in another person (usually a young child or sometimes an adult or animal) under the care of the person with the disorder. It is currently understood as including the condition commonly known as Munchausen syndrome by proxy (MSBP) and is also often termed as medical child abuse.

Signs and symptoms

Warning signs that raise the possibility of this disorder include the following:

  • Problems that are unexplainable, persistent, or resistant to interventions that "should" work, after adequate evaluation and treatment attempts

  • Serious discrepancies among the history, clinical findings, and patient's general presentation

  • A working diagnosis of a disorder so rare that maltreatment is more likely

  • Symptoms and signs that occur only in association with one person and/or schedule (e.g., weekly, monthly) or in the absence of a family member (e.g., whenever one parent goes on a business trip)

  • A caregiver who reports that records are missing or who insists on hand carrying them without adequate reason

  • Families in which other members have had problems similar to the patient's presenting problem, without adequate explanation

  • A caregiver who habitually relates dramatic, exaggerated, or improbable events in relation to her/himself or others

  • A caregiver with previous medical or nursing experience, an extensive history of illness, or a history of factitious disorder

  • Other members of the treatment team are suspicous

These warning signs do not mean that FDIA is occurring, but rather indicate a need for futher investigation and verification of what is occurring.

See Presentation for more detail.


Evaluation must be based on specific findings, with investigations aimed at establishing what is going on and why. Laboratory tests, imaging, and other studies performed should be appropriate to the presenting problem, but not inappropriately pursued. If factitious symptoms or signs are found, attention should be given to detecting the potential method by which they are occurring. Evaluation may also need to include other family members. 

During assessment of a potential victim in a case of FDIA, clinicians should ask themselves the following questions:

  • Is the potential victim safe?

  • Is the potential victim's condition consistent with the caregiver's description?

  • Have records or reports of previous evaluations and interventions been verified with the practitioner independently of the caregiver's report? Do they endorse the problem as the caregiver reports it?

  • Does evidence support the potential victim's reported condition?

  • Has any objective observer witnessed the problem?

  • Is treatment being provided to the potential victim primarily because of someone's persistent demands?

See Workup for more detail.


Case management of probable or confirmed FDIA involves the following, many of which will occur simultaneously:

  • Making sure that the victim is as safe as possible and continuing any necessary care.

  • Gathering further information/evidence to support, confirm, or refute the diagnosis and build a court case if court action is anticipated.

  • Reporting suspected abuse to protective services as required by law and cooperating with agency personnel and actions.

  • Educating all involved personnel about FDIA, the risk to the patien, and appropriate management.

  • If possible, involving a qualified FDIA consultant to help with case managment from suspicion onward.

  • Psychotherapy should be offered to the perpetrator, the victim(s), and the family. Pharmocotherapy may be appropriate when the perpetrator has comorbid psychiatric conditions that are amenable to treatment. The family requires careful long-term monitoring, especially because of the danger that the perpetrator could move the family and seek to perpetrate such behavior in a new location. 

See Treatment for more detail.



A study from 1992 suggested that parental responses to children occupy a continuum. [1] At one end of the continuum is the parent who exhibits classic neglect, disregarding symptoms in a child who is truly ill. At the other end is the parent who fabricates or generates factitious symptoms in a child who is otherwise healthy. In between are the parents who are appropriately concerned about a child’s symptoms and who make appropriate efforts to seek care for the child.

Factitious disorder imposed on another (FDIA; formerly factitious disorder by proxy) has as its cardinal characteristic the production or feigning of problems in another person (usually a young child, but sometimes an adult or animal) under the perpetrator’s care. Although this disorder is not rare, it can be difficult to detect and confirm. [2]

In the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), [3] the diagnosis of factitious disorder imposed on another includes the disorder originally known as Munchausen syndrome by proxy (MSBP), [4] a term that continues to be commonly used by the general public. It is a covert, potentially lethal, and frequently misunderstood form of abuse (typically, child abuse). It was first identified by Sir Roy Meadow [4] in relation to cases of two mothers’ tampering with urine specimens. At the time, Munchausen syndrome (now called factitious disorder) was the term applied to people who presented themselves as ill. The name recalls the storied Baron von Munchhausen, who went from place to place during his career and often told tall tales.after his retirement from the military. 

Many people, professional and lay, had a difficult time believing that parents would harm their children in this way. An accumulation of documented cases and its “discovery” by popular media gradually brought wider recognition, although motivations and dynamics are still poorly understood. Nor has it always been clear whether it should be regarded more as a form of abuse or a mental illness. For example, the term medical child abuse (MCA) was proposed by Roesler and Jenny to describe the excessive, unnecessary, and harmful (or potentially harmful) medical or surgical treatments imposed on the child at the instigation of a caregiver. [5]  

In 2002, the term pediatric condition falsification (PCF) was introduced by the American Professional Society on the Abuse of Children (APSAC) to describe the condition in the abused child. APSAC defined it as comprising factitious disorder by proxy (as the disorder was then known) in the perpetrator and PCF in the victim. In 2018, the APSAC issued updated clinical and case management guidelines for FDIA/MSBP. [6]

FDIA is not a psychosis. The caretaker voluntarily and consciously simulates, falsely reports, and/or induces symptoms of a problem and then takes the victim to seek professional attention, disavowing knowledge of the source of the problem. The deception may arise from a desire for attention, anger, a need for control over others, or other intangible motivations. Perpetrator dynamics are poorly understood in most cases. Note that if the primary motivation appears to be material gain (e.g., receipt of money for a disabled person), the principal diagnosis is malingering. However, in many cases of FDIA, there is tangible gain that appears to be secondary to the non-tangible gain. FDIA and malingering are not mutually exclusive. [7]

Most of the symptoms in known and documented cases are physical complaints; feigning of behavioral symptoms appears to occur to a lesser extent. However, the full range of presentations is essentially unlimited. Physical presentations commonly include vomiting, diarrhea, respiratory arrest, asthma, seizure, recurrent conjunctivitis, clumsiness, syncope, fever, infection, bleeding, failure to thrive, or electrolytic disturbance. 

Clinicians are trained to elicit the history of a sick child from his or her parents. This standard approach carries extra risk if FDIA is occurring. Typically, a perpetrator—usually the biological mother—recounts serious symptoms that cannot be ignored. Often, these symptoms depend on observation (e.g., seizures, apnea). These reports may result in the performance of many laboratory tests and other procedures, including hospital admission and surgery.

Most known victims of FDIA are infants and young children, although cases have been reported of dependent adults and animals. Victims who are able to speak for themselves usually do not, out of motivations such as fear, belief in what the perpetrator has told them about their condition, or loyalty to the abuser. Victims not uncommonly suffer serious injury or even die.

Inconsistencies, improbable findings, or inexplicable test results should raise the suspicion of FDIA. For example, polymicrobial sepsis in a central line is extremely rare and should elicit consideration of the possibility of tampering. As another example, finding carbamazepine in the blood of a patient to whom the drug was not prescribed or finding a high level in a patient in whom it was discontinued should suggest possible FDIA. Of course, other reasonable potential causes must be ruled out before a conclusion is made that FDIA is occurring.

A multidisciplinary team approach is recommended to confirm the diagnosis and protect the victim. Long-term psychiatric follow-up is necessary for both the child and the perpetrator, although the outcome for perpetrators is often poor. Educating providers in healthcare, protective services, and other fields about the disorder and establishing local task forces may facilitate timely diagnosis and management. These systems may, unknowingly, play a partial role in the perpetration of FDIA.

Diagnostic criteria (DSM-5 and American Academy of Pediatrics)

In DSM-5, factitious disorder is divided into the following 2 types: [3]

  • Factitious disorder imposed on another (formerly factitious disorder by proxy; MSBP)

  • Factitious disorder imposed on self (more chronic and severe forms of which are commonly labeled as Munchausen syndrome [8] )

When an individual falsifies illness in another (eg, a child, an adult, or a pet), the diagnosis of the perpetrator is factitious disorder imposed on another. The specific DSM-5 criteria for factitious disorder imposed on another are as follows [3] :

  • Falsification of physical or psychological signs or symptoms, or induction of injury or disease, in another, associated with identified deception

  • The individual presents another individual (ie, the victim) to others as ill, impaired, or injured

  • The deceptive behavior is evident even in the absence of obvious external rewards

  • The behavior cannot be better explained by another mental disorder, such as delusional disorder or another psychotic disorder

As noted, this diagnosis is applied to the perpetrator, not the victim; the victim may be given an abuse diagnosis. Depending on definitions in the area where the abuse has occurred, various categories of abuse and/or neglect may apply. For example, educational neglect might be considered if the feigned problem has led to many school absences. [9]  Under no circumstances should the diagnosis of FDIA be construed as the perpetrator “having” a mental disorder that causes, accounts for, or “explains away” the behavior.

For purposes of comparison, the specific DSM-5 criteria for factitious disorder imposed on self are as follows [3] :

  • Falsification of physical or psychological signs or symptoms, or induction of injury or disease, associated with identified deception

  • The individual presents himself or herself to others as ill, impaired, or injured

  • The deceptive behavior is evident even in the absence of obvious external rewards

  • The behavior cannot be better explained by another mental disorder, such as delusional disorder or another psychotic disorder

In both types of factitious disorder, the duration is specified as either a single episode or recurrent episodes (≥2 events of falsification of illness or induction of injury).

According to the American Academy of Pediatrics Committee on Child Abuse and Neglect, the healthcare worker must substantiate the credibility of the signs and symptoms, determine the necessity and benefits of the medical care, and question who is the instigator of the evaluations and treatments. To make the diagnosis, the presence of the following 2 factors must be established:

  • Harm or potential harm to the child (or other victim) from excessive intervention

  • A caregiver who is fabricating illness or pursuing unnecessary treatment; the motivation of the perpetrator is not important in diagnosing the abuse (as it has sometimes been considered in other diagnostic criteria)

The latency period between the start of abuse and its discovery can be relatively long. Several barriers often delay the timely detection and confirmation of FDIA, including the following:

  • Failure to consider it in the differential diagnosis

  • Lack of knowledge about FDIA on the part of pediatricians and other professionals [10]

  • Uncertainty with regard to differentiating normal parental anxiety or concerns from a pathologic seeking of care

  • Tendency of the provider to believe the history the caregiver provides

  • Ability of the caregiver to present a highly persuasive and compelling history, sometimes accompanied by fabricated documentation

  • Involvement of several providers, often in different setting and sometimes different cities, states, or even countries

  • Fear of making a false accusation and its subsequent legal repercussions

  • Lack of collaboration or poor relationships among medical, legal, and child-protection agencies; reluctance to become involved in a child protective case

  • Reluctance to separate the victim from the family to evaluate the victim's medical condition without the caregiver's involvement

  • Reluctance to admit the possibility that the caregiver has been fooled



There is no pathophysiology known to be associated with factitious disorder imposed on another (FDIA) perpetration. 



Most cases of factitious disorder imposed on another (FDIA) have been reported in the pediatric medical literature. The exact psychopathology and any pathophysiology of most perpetrators are unknown.

A number of theories for the pathogenesis of FDIA have been postulated. The psychodynamic literature emphasizes a reaction to loss or a way to obtain attention and nurturing, a way to feel powerful, or a way of just acting out as possible explanations. Some investigators offer unspecified brain dysfunction as an explanation. The abuser may have experienced abuse as a child or may have failed to develop empathy for some unknown reason. Other theories include rejection of the child, perhaps resulting in part from an interruption in early bonding, [11]  a pathologic relationship with the child, psychological rewards received from the medical community or other high-status individuals because of the sick child, or a disguised need for help.

The following psychiatric comorbidities may be present:



United States statistics

The incidence and prevalence of factitious disorder imposed on another (FDIA) in the United States, though not precisely known, [12] are almost certainly higher than was once estimated. In 1991, Schreier and Libow surveyed 880 pediatric neurologists and 388 pediatric gastroenterologists in the United States, with return rates of 21.8% and 32.4%, respectively. [13] Among physicians who responded, 212 reported contact with 192 suspected and 273 confirmed children victimized by FDIA.

It is estimated that approximately 625 cases of poisoning and suffocation attributable to FDIA can be expected in the United States each year. This estimate basically refers to clinically significant cases diagnosed or treated in a hospital setting and may underestimate the number of cases seen in outpatient clinics and nonmedical settings.

A 2004 meta-analysis showed that pediatric condition falsification (PCF) was the cause of 0.3% of all cases of ALTEs. [14] Another quite controversial report suggested that intentional suffocation was the cause of about 10% of all cases of SIDS. [15] In a series of 135 cases reported by K. Feldman et al., 25% of the children had renal or urologic related issues. [16]

International statistics

FDIA is increasingly recognized and reported worldwide in the medical literature. More than 700 cases from 52 countries have been reported; however, these reflect only the most severe cases and cases that have been substantiated. The true overall prevalence is unknown. Cases have come from many developing, nonmedicalized societies as well as developed countries. [17]

One group found that 1% of children with asthma had been subjected to FDIA. [18] In another report of children with food allergies, 16 of 301 children (5%) had been subjected to FDIA. [19]

In an English town with a population of 200,000, 39 cases of intentional suffocation of children were reported over 20 years (1 case per 25,000 population). [20] A survey by the British Pediatric Association Surveillance Unit found 128 cases of reported MSBP in the United Kingdom and Ireland over a period of 2 years, with an incidence of 2.8 cases per 100,000 children younger than 1 year and an incidence of 0.5 cases per 100,000 children younger than 16 years. [21]  This last study was notable for its highly conservative process to confirm MSBP, which may undercount the number of actual cases.

Age-related demographics

Demographics of perpetrators

Demographics of perpetrators is unknown, but appear to be largely people in their child-rearing years.

Demographics of victims

The abusive behavior characteristic of MSBP commonly starts early in the victim’s life; infants and young children are those most frequently exposed to MSBP. According to Rosenberg, the median age of the child at the time of MSBP diagnosis is 39.8 months, though children older than this have also been affected by caretakers with this condition. [22] McClure et al reported a median victim age of 20 months at diagnosis, with a distribution skewed toward younger individuals. [21]

A report by Meadow found that suffocation began between the first and third months of life and lasted 6-12 months or until the patient died. [23] In a review of 451 published cases, Sheridan found that affected children were usually younger than 4 years. [24] Awadallah et al reported a 14-year-old MSBP victim and 9 victims older than 6 years who were referred to child protective services between January 2001 and June 2003. [25] In their literature review, they also found 42 victims reported from 1966 to 2002. A 2015 review of adult victims of FDIA disclosed that these victims ranged from 21 to 82 years old. [26]

Demographics of victim's siblings

Siblings may suffer the same abuse that the reported FDIA victim receives, and from the same parent. According to Rosenberg, 8.5% of siblings were abused. [22] In a series of 27 infants who were suffocated, 48% had a sibling who allegedly died of Sudden Infant Death Syndrome (SIDS). [23] A survey of pediatric neurologists and gastroenterologists found that almost 25.8% of children who were abused had siblings who also were abused.

In a survey of 83 index cases of FDIA, 15 children had 18 siblings who previously died, and 5 of these deaths were classified as SIDS. In another report, 28 children subjected to FDIA had 41 siblings, 12 of whom died suddenly; 11 deaths were classified as SIDS, and 1 was attributed to gastroenteritis. Five parents admitted to killing 9 of the siblings. A meta-analysis of 451 cases of FDIA with 210 siblings revealed that 61% of the siblings had symptoms and 25% had died. [24]

In a series of 135 victims reported by K. Feldman et al from 1974 to 2006, 31 of 34 children had siblings who were also victimized; 6 of these siblings died. [16]

Sex-related demographics

Demographics of perpetrators 

In a 2017 review of 796 cases of FDIA, the mother was the perpetrator of the child’s illnesses in 95.6% [11]

Demographics of victims

Boys and girls are exposed to FDIA with approximately equal frequency.

Race-related demographics

To date, no racial or ethnic predilection for this condition has been determined. However, most of the perpetrators in published reports have been white, when race was mentioned at all.



Prognosis of perpetrators

Generally, prognosis in factitious disease imposed on another (FDIA) depends on perpetrator characteristics.Those with a good prognosis—admittedly rare--have the following characteristics:

  • They understand, admit to, and assume responsibility for their behavior [27]
  • They can improve their coping skills
  • They can place their victim’s needs above their own

Patients with a poor prognosis may exhibit the following signs:

  • They demonstrate a high degree of denial
  • They are uncooperative or noncompliant with therapy
  • They have a personality disorder

Prognosis in victims

Reported morbidity and mortality in victims vary considerably, ranging from infection of unknown origin to unexplained death. The incidence of death and serious medical complications is not precisely known. Mortality ranges from 9% to 31% among index cases, with most investigators reporting a mortality of 9–10%. In a review of the literature, Sheridan reported a 6% mortality and a 7.3% long-term injury rate for index cases. [24]

Morbidity may result either from the abuse or from multiple interventions performed by unwitting medical and other providers. McClure et al. reported that 122 of 128 abused children were hospitalized as a result of the abuse; of the 128, 119 received unnecessary invasive interventions, 45 had major medical illnesses, 31 had minor physical ailments, and 8 died. [21] In a survey of 51 clinics treating infant apnea, 54 of 20,090 children had been subjected to FDIA. [28] Cardiopulmonary resuscitation was performed in 21 of the 54, and 24 were hospitalized.

Children subjected to FDIA present not only with induced physical ailments but also with fabricated psychological symptoms. Like those abused in other ways, children subjected to FDIA can also have long-term emotional, psychological/behavioral, and educational disorders. Lacking good parental models, it is possible that they will treat their own children as they were treated.

McGuire and K. Feldman described 6 children who had behavioral problems, including feeding disorders in infants; withdrawal, hyperactivity, and oppositional behaviors in preschoolers; and conversion symptoms in older children and adolescents. [29] Older children often tolerated and cooperated with their parents in their own abuse and fabricated medical illnesses of their own.

Bools et al reported the outcome of 54 children aged 1–14 years who were subjected to FDIA. [30] Several of them had behavioral problems, such as emotional and conduct disorders, achievement problems, nonattendance at school, fears and avoidance of specific places or situations, sleep disturbances, or features of posttraumatic stress disorder (PTSD). Boys had more disturbances than girls. Most of the children who remained with their mothers were exposed to repeated fabrication or were described as having other problems. Children with unacceptable outcomes were older than others at the time of abuse and were more likely to have siblings who had also been subjected to abuse.

Libow reported the results of a 33-item questionnaire administered to 10 adults who identified themselves as survivors of FDIA during childhood. [31] At the time of abuse, the respondents felt unsafe and unloved by their parents. As children, they had emotional stress and serious depression. They also reported problems with school and education as a result of absenteeism, lack of attention, or anxiety. As adults, they had insecurity, low self-esteem, depression, and symptoms of PTSD.


Patient Education

There is no evidence to suggest that education of the factitious disorder imposed on another perpetrator is useful, as the perpetrator’s problem is not a lack of knowledge. It may be important to educate the family and professional staff about FDIA. Education for the victim, such as the book by Feldman and Yates, Dying to be Ill: True Stories of Medical Deception, may be useful if/when the victim is able to understand psychological concepts.


Ethical and Legal Issues

The Federal Child Abuse Prevention and Treatment Act defines child maltreatment as “[a]ny recent act or failure to act on the part of a parent or caretaker, which results in death, serious physical or emotional harm, sexual abuse or exploitation . . . or an act or failure to act which presents an imminent risk of serious harm.” Factitious disorder imposed on another (FDIA) is usually difficult to prove; abusers are typically not caught in the act, and cases are usually based on circumstantial evidence.

When FDIA is suspected, the law requires physicians and other designated professionals to notify the authorities. Details will differ depending on the jurisdiction, but typically protective services must be involved for children and elders (all dependent adults in some jurisdictions). Reports to and action by animal welfare organizations and law enforcement may be important. It may be necessary for the reporter to educate the involved agency(ies) about the nature of FDIA and especially what has happened to the victim and how this behavior constitutes maltreatment. Offering written resources about how to investigate may be very useful for agencies and law enforcement personnel. [32]

Steps for the immediate protection of the victim may be initiated by law enforcement and/or protective services. Often this involves removal of the victim from the home, at least until the situation can be completely assessed. A court order may be needed to remove the victim from the perpetrator and/or keep the victim in a safe placement. In this case, or in later court proceedings, the personnel assisting with making the report may be required to testify.

Once protective measures are in place, the perpetrator should be confronted with the evidence. This confrontation should be planned carefully with protection in place for the victim, perpetrator, and involved professionals. The perpetrator will almost certainly deny the charge and may attempt to remove the victim from the hospital or placement. If allowed any contact with the victim, perpetrators may intensify the abuse in an attempt to “prove” that the problem is “real.” Perpetrators have also been known to decompensate mentally, threaten professionals, and kill or threaten to kill themselves. Criminal prosecution of the perpetrator is usually indicated, but almost all states lack specific criminal statutes governing FDIA abuse per se. Criminal prosecution may occur under charges such as assault or torture, but is often not pursued. 

The accused perpetrator is likely to continue to deny the behavior. Common defenses include assertions that the perpetrator “just did what the doctors said,” did not do what was alleged, is mentally ill and did not know what he/she was doing, and/or was compelled to commit the behavior due to mental illness. Other defenses have included attacks on the reporting professional (e.g., the doctor didn’t know what was wrong with the victim, so blamed the caregiver), or even that FDIA cannot be “proven” to exist.  Throughout the court process, a consultant and/or attorney with experience in FDIA cases can provide strategies to counter these defenses, present evidence in court, and support the professionals involved. 

FDIA cases can be very painful for those involved. It is difficult to admit that caregivers can abuse in this way. Often personal relationships have been formed with perpetrators, and these end in disillusionment and feelings of betrayal or shame. The professional who has been fooled by the perpetrator often feels embarrassed and ashamed about their part in the abuse. In spite of the difficulties, time commitments, and even dangers that may be involved with FDIA cases, both law (for mandated professionals) and ethics require that they be reported to protective services. Where the law and/or responding agencies are inadequate, the ethical response is to work for change. Changes may be effected through education, support for more training and funding, support for new legislation or legal reform, etc. It is recognized that busy professionals have limited time and energy, but a letter written, the offer to do a case conference, or support for an organization working for change can all be helpful.