Some people fake or induce illness or injury. Among their less gruesome methods, they might rub their skin to produce wounds, put salt in their urine samples, or pretend to be depressed. Some of those who fake and induce symptoms are malingering, that is aiming for money, drugs, to avoid work, or for some other “external incentive”. Others, who fit a diagnosis of Factitious Disorder Imposed on Another (FDIA), fake or induce symptoms in other people; the most common cases are mothers in their children (Cording and Carter 2021). And yet others fake or induce symptoms in themselves because they want to adopt the sick role, perhaps for the care, the attention, the sympathy, the admiration, the drama, or the delight in duping doctors and nurses. These people know what they are doing and they do it deliberately. They have what was called “Munchausen’s Syndrome” and is now called Factitious Disorder Imposed on Self (FDIS). They are the subject of this paper.

People with FDIS often cause physical harm to themselves, sometimes very serious harm up to and including death. But they also cause harm to others, especially by diverting scarce health care resources away from those who need them. Sometimes, as we shall see, the costs are staggeringly high, over $1 million. Such extreme cases are admittedly uncommon. However, it would not be surprising if FDIS were becoming a greater problem for health care systems. In the first place fabricating illness and injury on the internet has greatly increased. Some of this behavior is factitious (Giedinghagen 2023) and some people on the internet may well come to behave factitiously in health care settings. Moreover, the internet and support groups make it easier to learn how to fake or induce symptoms accurately and to demand specific treatments, thus reducing the barriers to entry for unnecessary medical treatment.

Should people with FDIS ever be held liable for any harm to others that they do? If not, why not? People with FDIS are not held liable in practice whereas ordinarily those who knowingly and deliberately cause harm to others are held liable, and that includes people who resemble FDIS patients in some respects. While I cannot find a quantification of their total, an internet search easily finds cases in which malingerers have been prosecuted, for instance for welfare fraud, or fraudulently claiming compensation (Daily Telegraph 2024). A search also easily finds convictions of those who fit the diagnosis of FDIA (Lopez 2024).Footnote 1 But the only cases I can find where people with FDIS were prosecuted have been where they fraudulently acquired money, such as a woman who raised funds in Auckland in 2016 for cancer she did not have (Howie 2016), and a woman in Arizona in the 1990s who impersonated an insurance official and told her hospital the bills were covered (Feldman 1995).Footnote 2 Factitious behavior seems never to be prosecuted for the harm of using up scarce health care resources. Nor have I come across any civil cases for recovery of costs.

One might think FDIS patients should not be held responsible for practical reasons, such as the difficulty of gathering evidence; or because FDIS patients would not be deterred; or because it would be too cruel to hold them responsible. But these reasons, I shall argue, are unlikely to justify exempting all those with FDIS from liability for factitious behavior even if they can excuse or mitigate in some cases. My main aim, however, will be to show that people with FDIS should not be excused on the grounds of their mental disorder.

Because liability for people with FDIS has not been discussed theoretically and has little case law, what I say will be an overview, aiming for breadth rather than depth. Everything in this paper could be considered in more detail, such as the nature of the disorder, its connection to rationality, and the jurisprudence of excuses, which changes from time to time and place to place. I also take no stand on the form any punishment might take, whether prison, fines, community service, or whatever.

1 What is factitious disorder imposed on self?

The classification of mental disorders is rarely straightforward, and the criteria for FDIS have shifted around over the years. Here are the current DSM 5 criteria, all of which must be satisfied for a diagnosis (APA 2013).

A: Falsification of physical or psychological signs or symptoms, or induction of injury or disease, associated with identified deception.

B: Individual presents self as ill, impaired, injured.

C: Deceptive behavior is evident even in absence of obvious external incentives.

D: Not better explained by e.g. delusional or other psychotic disorder.

Criterion A allows both faking and inducing. An example of faking is putting salt in a urine sample; an example of inducing is contaminating an intravenous line with faeces. Requiring that the faking or inducing be deceptive differentiates FDIS from other self-harming, where the aim might be to distract oneself from intrusive thoughts or to punish oneself rather than to cause others to believe one has a condition one does not. Criterion B, in requiring that it is the self that presents, differentiates FDIS from fabricating symptoms in other people. Furthermore, criterion B, in requiring that the individual presents as ill, impaired, or injured, differentiates FDIS from the sort of self-harming that people try to conceal, such as by wearing long sleeves to hide cuts on their forearms. Criterion C is an attempt to differentiate FDIS from malingering. Malingering might be bad behavior but faking or inducing symptoms is not generally a mental disorder when done for an insurance payout, to avoid conscription, to get time off work, or for some other “external incentive”. By contrast, the FDIS patient is motivated by internal incentives, summarized in the past as “seeking the sick role”. Since we can have more than one motive for an action, a question arises about people who fabricate symptoms for the sake of both external and internal rewards: how weighty does the internal reward have to be for their behaviour to qualify as factitious?. Criterion D differentiates FDIS from other disorders. One is hypochondriasis, where people wrongly think they have a condition they do not; another is conversion disorder, where, for psychological but not organic reasons, someone has genuine symptoms, an example being soldiers after battle who lose their eyesight because of the terrible scenes they witnessed.

People with FDIS vary in all sorts of ways. For instance, some fake on the internet while others are in and out of hospitals. People with FDIS vary in the conditions they fabricate and can be found in probably every medical discipline (Hausteiner-Wiehle and Hungerer 2020). They also vary in the nature and strength of their motives, which include seeking sympathy, care, attention, the drama of emergencies, the thrill of fooling medical professionals (so-called “duping delight”; see Lawlor and Kirakowski 2014, p. 212), and a sense of control (Feldman and Yates 2018; ch. 5). What people with FDIS have in common is that, at least to some degree, they know what they are doing. FDIS does not involve cognitive delusion, that is, those with FDIS do not believe that they are ill in a deluded way. They do understand that they are faking or inducing illness. We will come back to self-awareness.

We would be misled if we thought of people with factitious disorder as having strange desires. They rarely want pain and discomfort. Feldman and Yates write:

Although all patients with factitious disorder thrive on illness in some way, only a few derive psychological benefit from the symptoms themselves. Pain and incapacitation…are a means to an end only⸺to be endured, not enjoyed (Feldman and Yates 2018, p. 153).

People with FDIS often realise that what they do has costs to them, both directly, due to, for instance, their surgery or their own bloodletting, and indirectly, for instance because they spend so much time and effort in planning and fabricating that it interferes with other goals. But, as we saw, they desire care, attention, and sometimes drama or gratifying their own sense of cleverness. These are not strange desires; who amongst us is without any of them to some degree? For instance, Trisha Greenhalgh, writing of her appendix operation in her classic book, How to Read a Paper, says, “I had a nice rest from work and, to be honest, I rather enjoyed all the attention and sympathy” (Greenhalgh 2006, p. 154). The odd thing about factitious disorder is not the desires but the preference ordering, the willingness to lie and suffer unnecessary medical treatment because they so strongly want the sick role (Hamilton, Feldman, and Janata 2009).

The preference ordering of FDIS is philosophically puzzling. It is unusual, but is it irrational, or in some sense incorrect? To be sure, factitious behavior might be affected, in unremarkable ways, by biases, self-deception, wishful thinking, and other factors common in human behavior. Nonetheless, the behavior of people with FDIS is rational in the sense of rationally selecting means to fulfil their ends. If factitious behavior is irrational, it is not because of making such means-ends mistakes as using green ink instead of red to fake a loss of blood. The irrationality, if there is any, must lie in their balance of ends. It is, though, controversial whether a person’s balance of ends can be said to be irrational or wrong (Wilkinson 2025; ch. 4). Some philosophers might say that factitious behavior can be crazy but not irrational (Hubin 1991, p. 23); others that it is obviously irrational, something that only could be denied by those who wrongly conceive of rationality as purely instrumental (Gert et al. 2006, 7–8; Nagel 1986, p. 155).

To finish this sketch of FDIS, note that almost every writer on this disorder says something along these lines:

Individuals with Factitious Disorder Imposed on Self often do not provide accurate histories or access to their past medical records. As a result, systematic data regarding the onset and development of their factitious illness behavior and its long-term outcomes are extremely limited (World Health Organization 2024).

People with FDIS are “elusive” (Lawlor and Kirakowski 2014, p. 210; Feldman and Yates 2018, p. 134). Still, it seems widely accepted that a “substantial majority of individuals identified with Factitious Disorder Imposed on Self are female.”Footnote 3 Moreover, health care professionals are overrepresented; one very broad estimate is that 22–66% have medical qualifications (Hausteiner-Wiehle and Hungerer 2020, p. 454). People with FDIS can also have other mental disorders, such as Borderline Personality Disorder. These other disorders might affect their liability, a complication I must set aside (Kinscherff 2010). Lastly, estimates of incidence vary greatly but here is one estimate: “A 1-year prevalence of around 1% (to 5%) is usually assumed in clinical populations” (Hausteiner-Wiehle and Hungerer 2020, p. 454).

2 Crimes and harms to others

Factitious behavior often harms the people with FDIS themselves. But it also often harms other people, although usually indirectly. First, factitious behavior can be expensive. One extreme case involved a woman taking busulfan, a chemotherapy drug, resulting,

in life-threatening bone marrow suppression, bilateral aseptic hip necrosis, transfusion-dependent thrombocytopenia and a chronic pain syndrome. Her treatment was complicated by noncompliance with prescribed treatments and polymicrobial sepsis possibly secondary to the self-injection of feces into her central line. To date, the total cost of care for the treatment of this patient’s medical complications secondary to her ingestion of busulfan exceeds $1,100, 000.00 (Bright et al. 2001, p. 433).

One might deflate this cost on the grounds that US health care is over-priced, but then one would have to reflate again if the patient has cost more since and anyway that was the cost in 2001 dollars. Of course, this is an extreme case, although not unique (see other million-dollar cases reported in Australia and Italy by Liu et al. 2025). But even less extreme cases can be expensive. For instance, another cost estimate of 33,681.21 Euros was given for one patient who went to several Parisian hospitals (Hoertal et al. 2012). In some places, these costs might be initially borne by insurance firms, and subsequently by those who have to pay higher premiums. However, in public health care systems it is likely to be patients who bear the costs of not being treated when the people with FDIS needlessly and deceptively use up scarce resources. A second harm to patients is this:

lies about the sick role… compromise the effective treatment of authentically ill patients. …FD undermines the ability of doctors to trust patients who present with unusual or perplexing signs and symptoms (Hamilton, Feldman, and Janata 2009, 27).

Third, people with FDIS cause difficulties for medical teams, with staff feeling cheated or duped (Yates and Feldman 2016, p. 20). It would not be surprising if factitious behavior also split teams, with some believing their patients while others see them as exhibiting FDIS.

Should these harms be treated as crimes? Some writers compare the effect of factitious behavior on medical trust with the harm of impersonating a police officer, which is criminalised in many jurisdictions (Hamilton, Feldman, and Janata 2009). As another analogy, people who call the police deceptively can be prosecuted for wasting police time. These analogies suggest reasons to create new offenses. However, some of the behavior of FDIS may be an offense already in some jurisdictions, where laws criminalise obtaining services by deception.Footnote 4 And yet, as I said earlier, people with FDIS are at most rarely and possibly never prosecuted for causing these harms.

3 Deterrence, consequences, compassion

Whether to criminalize behavior, whether to prosecute it, even whether to investigate it, are decisions that depend on all sorts of considerations. My main focus will be on one of these, whether factitious behavior is blameworthy. In the rest of this section, however, I shall briefly mention some other considerations. These are deterrence and other consequences, practical problems in health care, and compassion.

Insofar as an offense is created to deter bad behavior, it would to that extent be pointless and harmful to punish somebody if either they would not be deterred or if no one like them would be. Quite plausibly, people at the severe end of factitious disorder would not be deterred. Why would they be put off by the remote risk of punishment when they are willing to risk their health and their lives? We cannot, however, assume that they would be immune to deterrence. Perhaps a criminal conviction would be more of a deterrent to factitious behavior than the physical harms it causes. After all, people sometimes choose to die rather than be shamed. We simply do not know whether punishment would deter factitious behavior, not least since people with FDIS have not been prosecuted. Nor do we know the answer to questions about other consequences. Would holding people criminally liable for deceptive factitious behavior encourage more non-deceptive self-harm, such as blatantly inserting objects into the urethra?Footnote 5 Would it discourage people from factitious behavior, thereby preventing harm to themselves as well as others, or steer them into less harmful deception, such as covering themselves with bandages before putting their pictures on social media? We can tell plausible-sounding stories, but we lack evidence.

Would it be practical to prosecute FDIS cases? It may be difficult to get proof and health professionals and hospitals may not want to get involved. Quite likely, these practical reasons should have some weight, but they do not warrant exempting from responsibility all cases of factitious behavior. Although it is difficult to prove that people are faking, certain red flags can form a pattern. People can be caught bloodletting, tampering with samples, or having vials of fake blood; they might have test results that are wildly inconsistent with known facts about live human bodies, such as extremely high temperatures (Hausteiner-Wiehle and Hungerer 2020, p. 452); their symptoms might be inconsistent with the normal course of illness, such as grossly exaggerating problems in memory by claiming to forget which hand holds a coin (Schroeder et al. 2012). Moreover, the problems of gathering evidence arise in cases of FDIA, where people fabricate symptoms in others and, as we saw, some of them have been successfully prosecuted. Thus, on its own, absence of proof seems unlikely to justify the near-complete absence of prosecutions.

Health professionals and hospitals might not have the time or resources to lay complaints or participate in a trial. They might not want to play any part in prosecuting their patients. And they might fear liability, such as a counter-suit that accuses them of negligence or incompetence. However, these reasons seem insufficient to rule out ever prosecuting FDIS cases given that they are likely to arise in cases of malingering and FDIA which, as mentioned, have sometimes been successfully prosecuted. Perhaps we should conclude that if it is worthwhile prosecuting factitious behavior that harms others, the details of who should do so and how are still to be worked out.

Let me speak briefly to the idea of compassion or mercy. One might feel that people with FDIS have suffered enough, and it is true that those who use up a great deal of health care resources tend, in doing so, to suffer pain, discomfort, injury, and, in some cases, permanent damage. It may then seem cruel to hold them responsible or, if not cruel, too coldly and sternly just. I agree that compassion can be a reason not to punish, as when some dying prisoners are released early from their sentences on compassionate grounds. All I want to do here is make two comments on compassion that might help us determine how far it supports not holding people responsible for factitious behavior.

First, even if compassion is a reason against punishment, it may be outweighed. If holding the people responsible for deceitfully wasting resources would lead to less deceit and more resources for the patients who genuinely need them, then it may be more important than being compassionate to people with FDIS. But if holding people with FDIS responsible would have only the advantage of giving them their just deserts but did not deter them at all, then, to me at least, it seems better to be compassionate.

Next, let me invite the reader to test their intuitions in the light of this observation: it would be no more compassionate to exempt factitious behavior from punishment than it would be to exempt someone who was suffering for a reason unrelated to a mental disorder, such as an arsonist who burns himself while committing arson. If an FDIS patient suffers bad headaches and nausea from the infections that have induced in themselves, they would have no greater claim to compassion than someone who commits an equivalent crime while also, and unrelatedly, suffering equally-bad migraines. One might reply that the cases are different because with FDIS a mental disorder caused the behavior that in turn caused suffering; but then that suggests a concern not for compassion but for liability. It implies that it is not the fault of people with FD that they do what they do. It is liability we now consider.

4 Responsibility and mental disorders

The most likely principled reason not to hold people with FDIS responsible is that, while their conduct may be harmful, it is not blameworthy because of their mental disorder. Before asking whether this reason is a good one, let us remind ourselves why one might want to hold someone else responsible or indeed to be held responsible oneself. In the first place, if you hold people responsible, they will generally at least try to control their behavior. If they do control their behavior, then they would do less harm to other people. They would also benefit from being part of a system of liability, because others would then control their behavior towards them (Santoni de Sio 2011, p. 304). Even those convicted of theft benefit from others not stealing their property.

Moreover, responsibility is inseparable from autonomy. If we want the benefits of being regarded as autonomous, in particular the benefit of making decisions about our own lives for ourselves, we must accept our responsibility. In the context of mental illness and disorders, a patient advocates’ movement has campaigned to abolish or greatly attenuate criteria for competence, so that even those who meet diagnostic criteria for mental disorders would be entitled to choose for themselves (Scholten et al. 2021). But one cannot have it both ways, claiming to be capable of deciding for oneself while incapable of being responsible for one’s behavior.

We should not regard being held responsible as just a cost of being treated as autonomous. To be held responsible is to be publicly acknowledged to be autonomous and to be treated as an agent and not a natural thing or a “helpless victims of external circumstances” (Santoni de Sio 2011, p. 304). Furthermore, in the opinion of some, to be held responsible also makes us autonomous (Szasz 1963, p. 255). It may even be, as Philipp Wichardt suggested to me, that being treated as responsible would be of therapeutic benefit to FDIS patients, for instance in changing how they see their condition, or in encouraging them to seek help (see also Glover 2014, p. 304).

The reasons to hold people responsible are all rebuttable. What if it turns out that people with FDIS have difficulties controlling their behavior? Whether any such difficulties would be reason enough not to hold them responsible would depend not only on what these difficulties were, but also on the standard to which they are held; and this standard will in turn depend on the context (Sinnott-Armstrong 2013, pp. 136-7). A clinician, a therapist, or a friend might quite rightly not hold them entirely blameworthy given the circumstances that drove their factitious behavior. The legal system might nonetheless rightly regard them as responsible because, unlike clinician, therapist, or friend, it has as one aim protecting other people. How, then, can we tell whether factitious behavior is under enough control for legal responsibility? The method I shall adopt is to consider the relevant legal defenses and see how well factitious behavior fits with them.

As an initial observation, having a disorder does not excuse someone from all liability. To use an example from Anthony Kenny, if an academic has delusions of persecution and is convinced that colleagues are plagiarising their work and conspiring against their promotion, they would not be excused if they, unrelatedly, kill their mother-in-law for an inheritance (Kenny 1984, p. 300). Even if a disorder causes criminal behavior, having a disorder is not enough to excuse in practice. Scarcely a week goes by without somebody in New Zealand being convicted of theft in order to fuel their gambling addiction. Moreover, as we saw, some people have been convicted for factitious behavior harming others, such as their children, even though FDIA is also a disorder in DMS 5. Perhaps what happens in practice is wrong, but the question nonetheless arises of what it is about a mental disorder that might excuse conduct.

What must be considered is whether and how a disorder connects to an excusing condition. These excusing conditions are variants of ignorance or compulsion (Hyman 2015, p. 77). Facts about FDIS, or any other mental disorder, are irrelevant to excuses unless they can be connected to these conditions. Thus if neuroscience found a part missing in the brains of people with FDIS,Footnote 6 or if genetics found FDIS to be hereditary, it would be irrelevant unless these findings could be connected to ignorance or compulsion (Morse 2019, 542). And while many of those with FDIS had unloving parents, chaotic upbringings, or were themselves the victims of factitious behavior by proxy, again they would not thereby be excused unless these findings can be connected to the excusing categories.

5 Insanity, ignorance, compulsion

In this section, we shall see to what extent FDIS fits within various standard legal defenses, all with the disclaimer that this overview must gloss over a great deal of variety in how excuses are understood and applied. We begin with the insanity defense, and then consider ignorance, irresistible desires, and duress.Footnote 7 Once we have seen the difficulties with excusing FDIS, we shall be able to see the flaws in the only serious philosophical analysis of FDIS, which claims that factitious behavior is ‘unvoluntary’.

Insanity defenses in Anglo jurisdictions follow the M’Naghten rules. A typical version, taken from Sect. 23 of the Crimes 1961 in New Zealand, is this: a person is not to be convicted if a disease of the mind makes someone incapable “of understanding the nature and quality of the act or omission or knowing the act or omission was morally wrong, having regard to the commonly accepted standards of right and wrong”.Footnote 8 By way of commentary, the rules unsurprisingly have an archaic quality deriving, as they do, from a panel in the House of Lords in 1843. Still, one can see why we might not want to hold people responsible if they could have no idea what they are doing, or, if they do know, not hold them responsible if they could have no idea that what they do is wrong. Also by way of commentary, it is both difficult and risky to establish insanity. It is difficult because the bar is high. It is risky because a successful defense exposes the defendant to the danger of being compulsorily treated for their disorder and that can involve being detained indefinitely. As a lawyer from the Floridian firm Kenneth Padowitz P.A. puts it, in assessing kleptomania as a defense to a charge of shoplifting, “You are better off pleading guilty. The penalty for shoplifting may not be as severe as getting confined in a mental hospital” (Kenneth Padowitz 2024; see also Ashworth 1991, p. 182).

I know of no cases where the insanity defense has been tested in the case of FDIS. Perhaps it never has. However, it seems most unlikely that factitious disorder would fall under the M’Naghten rules. The people who fake or induce symptoms know what they are doing. They do not resemble someone who strangles a person under the delusion that they are squeezing a lemon (Ten 1987, p. 124). They also probably realise their behavior is wrong by conventional standards, given that they try to conceal it and deny it. Furthermore, some research finds that many of those with FDIS feel guilt and shame about what they do (Lawlor and Kirakowski 2014, p. 213). At least some “loathe deceiving others” (Feldman and Yates 2018, p. 142) and, to quote one patient, “I had always known on some level that what I was doing was wrong” (Feldman and Yates 2018, p. 146).

Since ignorance is one of the standard categories of excuse, one might ask whether, or when, factitious behavior involves ignorance. People with FDIS could be ignorant about what they are doing and they could be ignorant about why they do what they do. As we have seen, writers seem to agree that people with FDIS more or less realise that they are inducing their symptoms, although “factitious behavior…may also occur in dissociative (unconscious, trance-like states)” (Hausteiner-Wiehle and Hungerer, 454). Indeed, the same patient’s behavior might be carefully planned on some occasions while at other times being more like a reflex (see “Polly” in Feldman and Yates 2018, p. 145). On the question of motivation, writers appear to disagree. On the one hand, some writers think FDIS always involves “unconscious motivations” (Van der Feltz-Cornelis 2002, 259). Fry and Gergel (2016, 570), in the course of recommending treating FDIS patients paternalistically, write that factitious behavior “strongly suggests both a lack of insight and control over their condition, which does not reasonably suggest self-determination”. On the other hand, Feldman writes, “Nearly every patient I have encountered…has been able to explain their behavior in a cogent (if not always precise) manner” (Feldman and Yates 2018, pp. 134-5). The apparent disagreement may not be real, in the sense that these claims could be true of different people, or the same people at different times.Footnote 9 Perhaps patients in therapy have been able to acquire enough insight to explain their motives whereas people not in therapy have not. Or perhaps people behave factitiously without insight at the start but later on acquire it.

Could ignorance be raised as an excuse for factitious behavior? Not knowing why one does something wrong is not in general an excuse. Doing something in a trance-like state, which might be true of some factitious behavior sometimes, could perhaps be an excuse, but one would presumably also need to demonstrate that one did not realize one had a tendency to be in such states. Someone who crashes a car during a seizure might be liable if they knew they were prone to seizures. They should not have driven. Analogously, if someone knows they are likely to engage in factitious behavior, they could take steps to avoid it, perhaps by warning clinicians or seeking therapy. In short, it is hard to see how ignorance could be used as a general excuse for factitious behavior even if it might succeed in some cases.

Let us now consider the argument that FDIS is, or is like, an addiction, and should be an excuse because addicts are not responsible for pursuing their addictions. Feldman writes: “I firmly believe that the majority of these patients are struggling with an addiction and that, like any addict, they are chasing a ‘high’’ (Feldman and Yates 2018, p. 135). Lawlor and Kirakowski (2014, 216) write: “In the case of FD it is proposed [i.e. Lawlor and Kirakowski propose] that the addiction is to occupying the sick role”. These writers also say that those with FDIS themselves often describe their behavior as addictive. They point to the overlap between factitious behavior and the behavior of drug addicts. For example, Feldman quotes “Meghan”:

My whole body yearned for illness. My life was like a hamster wheel: I would get the “fix,” end up in hospital, recover, and then go round again. I think people would be more accepting of patients with my condition if they knew we were addicted (Feldman and Yates 2018, p. 135).

Notice here the reference to a fix and to cyclical behavior, typical of addiction (see also Lawlor and Kirakoswki 2014, 216). Moreover, people with FDIS often display the ambivalence characteristic of many addicts. As Hausteiner-Wiehle and Hungerer put it: “Many of them have wanted to abandon the sick role, and the web of lies it involves, on several occasions” (Hausteiner-Wiehle and Hungerer, 456).

Whether or not addicts ought to be excused, we cannot be sure that all factitious behavior is addictive. The claim that FDIS is like addiction may be subject to a sampling bias. Feldman is reporting statements by his patients, rather than the many, perhaps most, who avoid treatment. Lawlor and Kirakowski analysed posts of two online support groups for people who self-identify as having FDIS, leaving out those who neither use online support groups nor identify as having FDIS. Some people with FDIS may accept their desires and the behavior that fulfils them and not try and fail to quit. Even Lawlor and Kirakoswki (2014, 214) say that 5% of the groups did not seek therapy because they had a “fear of recovery” i.e. did not want to stop what they were doing. As with other strong desires, perhaps some people with FDIS take a negative attitude towards theirs while others do not; or perhaps people’s attitudes to their desires change.

Even if FDIS is, or is like, an addiction, we would still need to connect the features of the disorder to an excuse. Notice that addiction is not generally a legal excuse, although it might be a mitigating factor. For instance, gambling addicts are held responsible for stealing to fund their addiction and alcoholics for killing people after driving drunk. Remember too that even those who meet the conditions for FDIA are sometimes prosecuted for the harm they do to others even though their behavior could be considered to be just as addictive as the behavior of those who induce or fake symptoms in themselves (Feldman and Yates 2018, p. 155). I make these points to cast some doubt on the idea that addicts should not be held responsible for their actions. That said, if we ask what it is about addiction, and by extension FDIS, that might excuse, one reason draws on the idea that to be addicted is to have strong desires (Feldman and Yates 2018, p. 135). One might then conclude that addicts are either unable to resist or cannot reasonably be expected to resist given the cost to them. But neither of these ideas seems likely to excuse factitious behavior in general.

No practical test exists to determine whether a desire was irresistible or whether it was simply a desire that was not resisted. Obviously, a defendant has an incentive to tell it one way. But what would even constitute independent evidence? (Ten 1987, p. 133; Santoni de Sio 2011, p. 294).Footnote 10 Furthermore, if we do consider FDIS to be a form of addiction, note that many writers think the desires of addicts are resistible, because addicts often resist them. Among the various bits of evidence are the following: most cocaine or marijuana addicts quit by their early 30 s without medical intervention (Heyman 2019, 30–32); people give up drugs when they otherwise stand to lose a great deal, such as their jobs as airline pilots or physicians (Heyman 2009, p. 86); of a sample of American soldiers addicted to opiates in Vietnam, only 12% met criteria for addiction after returning to the United States (Heyman 2009, 75–76); drug consumption is price-sensitive (Elster 2000, 168); even incentives to quit as small as a cinema ticket are moderately effective (Heyman 2009, pp. 105-7); smokers obey No Smoking signs or bans on smoking in aircraft, and have quit in very high numbers, thereby showing voluntary behavior (Baumeister 2017, p. 67).

Even if people with FDIS can generally resist their desires, perhaps it is unreasonable to expect them to bear the costs of doing so. We might think of FDIS not in terms of a defect of will but duress. To use a stock example, a bank teller would be at least excused and perhaps justified in handing over money if a robber credibly threatened them with serious harm. An obvious disanalogy with FDIS is that duress defenses typically involve threats by others. Even if that point was set aside, we would still have the difficulty of showing that the consequences of not fulfilling FDIS-desires were very severe. One way to understand a duress defense is that it is unfair or unreasonable to ask people to bear extreme burdens rather than do wrong. But of course, the law does not allow as an excuse for stealing that one needs to avoid the burden of bankruptcy or a collapsed marriage. Duress typically requires the burdens of death or serious bodily harm (Santoni de Sio 2011, p. 299). But in FDIS, these burdens, if they existed, would be the consequence of factitious behavior not the alternative that forces factitious behavior. The case is thus again disanalogous to the bank teller: the alternative for the teller to handing over the money is death or serious injury, whereas the alternative to factitious behavior is not dying or not being seriously injured.

Having seen the difficulties with excusing factitious behavior, we are now able to evaluate the only philosophical analysis I know of factitious disorder and voluntariness. This is an analysis by Bernard Gert, Charles M. Culver, and K. Danner Clouser that aims to show that people with factitious disorder ought to be excused from responsibility because their behavior, although intentional, is due to a volitional disability. In this respect, they say, factitious disorder belongs with compulsions, phobias, and addictions in a class of psychiatric disorders where the problems are of the will rather than belief (Gert et al. 2006, p. 174; 183–4).

Gert, Culver, and Clouser say that a person has a volitional disability when they do not act on coercive incentives. They either do what they have coercive incentives not to do, or do not do what they have coercive incentives to do. One can then see why they think that people with FDIS have a volitional disability. We all have coercive incentives not to fake or fabricate symptoms because, if we do fake or fabricate, we will suffer, or be at high risk of suffering, “significant evils, such as death or serious disability�� (Gert et al. 2006, p. 177). And yet people with FDIS fake or fabricate and so suffer. They do not act on their coercive incentives.

As against Gert, Culver, and Clouser’s argument, people can be responsible despite meeting their formal criteria for a volitional disability. Suppose a patient fakes or fabricates despite knowing the risks and thereby, to use their language, does not act on the coercive incentive. That someone does not act on a coercive incentive might indicate that they have something wrong with them, but they might just be trying to achieve a competing goal. Alexei Navalny did not act on a coercive incentive when he returned to Russia in 2021. He would certainly have had an excuse not to return; who could blame him, after he had already been poisoned once? But he did return, and he was responsible for returning, which is why one can appraise his conduct, for instance as courageous.

We get closer to an excuse when Gert, Culver, and Clouser write that: “The volitional ability to do X requires the ability to refrain from doing X” (Gert et al. 2006, p. 181). If a patient lacks the ability to refrain from factitious behavior, then perhaps they would not be responsible. But the formal criterion, of acting against a coercive incentive, does not entail the inability to refrain. The patient does not act on coercive incentives but perhaps they could have. It is the same problem that faced irresistible desires. One might know that someone acted on a desire, but that leaves open whether they could have resisted it. All one can tell is that they did not.

In sum, factitious behavior does not seem likely to fit within standard legal excuses even if FDIS is a mental disorder. Factitious behavior is not the result of gross ignorance, a demonstrably irresistible desire, or the need to avoid coercive costs.

6 Conclusion

It seems plausible to me that people whose factitious behavior is extreme have a mental disorder even though, under one description, what they do is rationally pursue their goals. What they want, whether attention, sympathy, concern, or excitement, is not remarkable; but what they are willing to do to get what they want shows that they have something wrong with them nonetheless. People with factitious disorder generally ought to have our sympathy and our compassion. Even so, factitious behavior can cause harm to others and when it does, the people who are faking or inducing symptoms may reasonably be held responsible, and perhaps ought to be if doing so would reduce these harms. I cannot say, because no one really knows, whether criminalizing factitious behavior would deter people with FDIS, or whether it would have acceptable administrative costs and effects on the relationship with health care providers. I cannot then say that the behavior ought to be criminalized, although equally a critic of criminalizing cannot say we know it would do no net good. But I can say that it would be reasonable to hold people responsible for factitious behavior because it is generally right to hold people responsible, and people with FDIS do not have an excuse that removes all responsibility.