Munchausen syndrome by proxy (MSBP) is a mental illness in which a person intentionally creates or lies about an illness in someone for whom they are a caregiver.
This disorder is rare, but it’s also likely underreported because it can be difficult to diagnose.
The victims of MSBP can suffer significant harm, so they should be removed from the situation as soon as possible.
Munchausen syndrome by proxy (MSBP) is a psychiatric disorder in which someone makes up symptoms or intentionally causes illness in another person. This is also known as “factitious disorder imposed on another.” MSBP is a rare condition, but it’s also likely underdiagnosed. It most commonly happens in a parent-child relationship. And 1 out of every 200,000 children under the age of 16 is a victim. But it can also affect adults who are dependent on someone's care, such as older adults or people with developmental delays. Here we’ll review the common behaviors of this condition. We’ll also describe what to do if you suspect someone is the victim of a person with this disorder.
There are two people affected in any MSBP diagnosis — the person with the condition and the person who’s victimized by them.
Someone with MSBP is more likely to be:
The parent of a young child
A young woman
In the medical field or familiar with medical terminology
Very involved in the victim’s care
Someone with other psychiatric disorders or personality disorders
Someone with a history of childhood trauma
But someone with MSBP doesn't have to fit these criteria. Given that the disorder is so rare, there’s variation in the typical person who has this condition.
The person who receives the care — or harm — from someone with MSBP tends to be:
A young child
An older adult of advanced age
Someone with a disability or chronic medical condition who relies on a caregiver
There are many ways that people with MSBP can create or lie about symptoms in those who are affected by their behavior. People with this psychiatric condition can:
Give poisons or medications that cause noticeable symptoms or side effects
Cause infections by injecting unsterile material into skin or intravenous (IV) lines
Withhold food or water to cause dehydration or malnutrition
Inject dye or blood into bodily fluids, or provide false fluid samples for testing
Suffocate someone to cause unconsciousness
Physically injure someone
Provide made-up medical records that document a false diagnosis or lab results
Encourage invasive or unnecessary testing or treatment
Victims of people with MSBP often have:
Frequent or repeated hospitalizations for unexplained symptoms
A long medical history without obvious cause for their symptoms
Recurrence or no improvement in their illness after medical care that should make them better
A caregiver who’s always present when the symptoms occur
Symptoms that get better when the caregiver isn’t around
MSBP can be hard to spot, and it’s very difficult to diagnose. This is partly because people with MSBP often appear to be very attentive caretakers. And they make it look like they’re advocating for those dependent on them. Plus, the victims are often unaware that they’re being abused. Or they may not be able to communicate it to ask for help.
There’s no clear answer to why people exhibit the behaviors seen in MSBP. One commonly cited reason is that people with MSBP exaggerate the caregiver role in their search for attention or sympathy. They’re gratified when they appear necessary and indispensable to someone else.
People with MSBP may receive financial gain or gifts from people or organizations who want to help. But that’s not thought to be the primary motivator for their behaviors. This is because people with MSBP still exhibit characteristic behaviors even in the absence of financial incentive. Individuals with MSBP often have poor insight into their behavior and the reasons behind it.
MSBP is a mental illness, and the caregivers diagnosed with it need psychiatric help. But MSBP is also a form of abuse. That’s because the victims of people with MSBP can get seriously hurt or even die from the actions of their caregivers.
If you suspect that someone is the victim of a caregiver with MSBP, it’s important to report your suspicions to child or adult protective services in your state, or report to the police. You may also report your suspicions to healthcare providers involved in the victim’s care. And if you think someone’s health or life is in immediate danger, call 911.
For children, you may also call the Childhelp National Child Abuse Hotline at 1-800-422-4453. This number is available 24 hours a day and 7 days a week. Professionals can help guide you to the appropriate resources to help a victim of someone with MSBP (or any other form of child abuse).
MSBP is a rare but potentially harmful psychiatric condition. Oftentimes, it’s unsuspected for years and is quite difficult to diagnose. This is especially true because the person with this condition often appears to be a concerned and involved caretaker. If you suspect that someone may be the victim of a person with MSBP, the first step is to report your concern to protective services. This way, both the victim and the caregiver with MSBP can receive the care and medical attention they need.
Bools, C., et al. (1994). Munchausen syndrome by proxy: A study of psychopathology. Child Abuse & Neglect.
Childhelp. (2021). The Childhelp National Child Abuse Hotline.
de Sousa, D., et al. (2017). Munchausen syndrome and Munchausen syndrome by proxy: a narrative review. Einstein (Sao Paulo).
McClure, R. J., et al. (1996). Epidemiology of Munchausen syndrome by proxy, non-accidental poisoning, and non-accidental suffocation. Archives of Disease in Childhood.
Meadow, R. (1989). ABC of child abuse. Munchausen syndrome by proxy. The BMJ.
Meadow, R. (1994). Who’s to blame—Mothers, Munchausen, or medicine? Journal of the Royal College of Physicians of London.