POSSIBLE UNDERLYING CAUSES AND DYNAMICS
Using structural magnetic resonance imaging, Yang et al6 found a widespread increase in white matter (23%-36%) in orbitofrontal, middle, and inferior prefrontal subregions, and a 36% to 42% reduction in prefrontal grey/white ratios in liars.
This white matter increase may predispose some individuals to pathological lying.
Lack of attention, negligence,and abuse can contribute to individuals developing a
need to lie.
Narcissistic personality disorder is very similar to pseudologia fantastica in that the former often tells exaggerated stories about the self to obtain constant attention and approval from others and overcome the underlying inadequate sense of self. In pseudologia fantastica, the stories are even more extreme and often not even possible, whereas the narcissist tells stories that are within the bounds of reality.
Borderline personality disorder and pseudologia fantastica can both cause patients to lie and not be able to acknowledge the truth from falsehood. However, in pseudologia fantastica, the other prominent features of borderline personality disorder (eg, impulsivity, self destructive behaviors) are absent.
Histrionic personality disorder shows similar dramatization and the extreme need for attention found in pseudologia fantastica. However, the former also manifests other histrionic features such as inappropriate sexuality, seductiveness, selfdramatization, and suggestibility.
Pervasive developmental disorder, which can be a co-occurring disorder, can be differentiated from pseudologia fantastica in that the former, although it can involve the telling of stories, the stories have a more preservative quality than those stories of
a person with pseudologia fantastica.