The sick role has been described with four aspects. First, the person is not able to will himself or herself back to health but instead must “be taken care of.” Second, the patient in the sick role must regard the sickness as undesirable and want to get better. Third, the sick patient is obliged to seek medical care and cooperate with his or her medical treatment. Finally, the sick patient is exempted from the normal responsibilities of his or her social role.

24.3.1 Diagnostic Criteria

For a diagnosis of factitious disorder to be justified, a person must be intentionally producing illness. His or her motivation is to occupy the sick role, and there must not be external incentives for the behavior. While DSM-IV-TR is clear that no external incentives can be present to meet the criteria for the diagnosis, it is rarely the case that there is absolutely no secondary gain for a patient (as the sick role automatically conveys some external benefits such as release from usual duties). In practice, clinicians will often diagnose patients with factitious disorder in the presence of some external gain as long as the external benefits do not appear to be a major motivation for the production of symptoms.

24.3.1.1 Factitious Disorder with Predominantly Physical Signs and Symptoms

Individuals with this subtype of factitious disorder present with physical signs and symptoms. The three main methods patients use to create illness are (1) giving a false history, (2) faking clinical and laboratory findings, or (3) inducing illness, such as by surreptitious medication use. Particularly common presentations include fever, self-induced infection, gastrointestinal symptoms, impaired wound healing, cancer, renal disease (especially hematuria and nephrolithiasis), endocrine diseases, anemia, bleeding disorders, and epilepsy.

True Munchausen’s syndrome fits within this subclass and is the most severe form of the illness. According to DSM-IV-TR, patients with Munchausen’s syndrome have chronic factitious disorder with physical signs and symptoms, and in addition have a history of recurrent hospitalization, peregrination, and “pseudologia fantastica” – dramatic, untrue, and extremely improbable tales of their past experiences. They are often very familiar with hospital procedures and use this knowledge to present dramatically during times when the factitious nature of their symptoms is least likely to be discovered.

24.3.1.2 Factitious Disorder with Predominantly Psychologic Signs and Symptoms

This subtype includes patients who present feigning psychological illness. They both report and mimic psychiatric symptoms. There are reports of factitious psychosis, homicidal ideation, and alcohol dependence in the literature and it is likely that patients feign psychiatric disorders across the full spectrum of mental illnesses. There are reports of false claims of being a victim of stalking or rape, and these cases are often diagnosed with a factitious psychological disorder such as post-traumatic stress disorder.

24.3.1.3 Factitious Disorder with Combined Psychologicl and Physical Signs and Symptoms

Some individuals present with simultaneous psychological and physical factitious symptoms, and some move between physical and psychological presentations over time. DSM-IV-TR was revised to account for patients who present with both psychological signs and symptoms, though this category of patients is the least well studied.

24.3.2 Epidemiology

The nature of factitious disorder makes it difficult to determine how common it is within the general population. Patients attempt to conceal themselves, thereby artificially lowering the prevalence. The tendency of patients to present several times at different facilities, however, may artificially raise the prevalence. Most estimates of the prevalence of the disease rely on the number of factitious patients within a given inpatient population. Such attempts have generated estimates that 0.5–3% of medical and psychiatric inpatients suffer from factitious disorder.

Patients with factitious disorder span a broad age range. Reports in the literature show patients ranging from 8 to 85 years. Case series suggest that the majority of people with factitious disorder are women – one case series found 78% of patients to be women while the majority of patients with the more severe Munchausen’s variant are men.

24.3.3 Comorbidity

All types of factitious disease show a strong association with substance abuse as well as borderline and narcissistic personality disorders.

24.3.4 Etiology

While factitious disorder appears to run in families, it is not known if this is explainable by genetic factors, environmental factors or both. Patients with factitious disorder are thought to create illness in pursuit of the sick role. For these patients, being in the sick role may allow them to compensate for an underlying psychologic deficit, act out angry impulses, or meet their underlying dependency needs.