326 Somatic Symptom and Related Disorders
order imposed on another, in  which the parent’s actions represent abuse and maltreat-
ment of a child), such criminal  behavior and mental illness are not mutually exclusive. The
diagnosis of factitious disorder emphasizes the objective identification of falsification of
signs and symptoms of illness, rather than an inference abou t intent or possible underly-
ing motivation. Moreover, such behaviors, incl uding the induction of injury or disease, are
associated with deception. 
Prevalence
The prevalence of factitious disorder is unknow n, likely because of the role of deception in
this population. Among patients in hospital sett ings, it is estimated that about 1% of indi-
viduals have presentations that meet the criteria for factitious disorder.
Development and Course
The course of factitious disorder is usually one of intermittent episodes. Single episodes
and episodes that are characterized as pers istent and unremitting are both less common.
Onset is usually in early adulthood, often after hospitalization for a medical condition or a
mental disorder. When imposed on another, the disorder may begin after hospitalization
of the individual’s child or other dependent. In individuals with recu rrent episodes of fal-
sification of signs and symptoms of illness and/ or induction of injury, this pattern of suc-
cessive deceptive contact with medical personnel, including hospitalizations, may become
lifelong. 
Differential Diagnosis
Caregivers who lie about abuse injuries in depe ndents solely to protect themselves from lia-
bility are not diagnosed with factitious disord er imposed on another because protection from
liability is an external reward (Criterion C, th e deceptive behavior is evident even in the ab-
sence of obvious external rewards). Such caregi vers who, upon observation, analysis of med-