Munchausen's syndrome by proxy (recently renamed fabricated or induced illness) is a rare form of child abuse, but relatively little is known about the psychopathology of the perpetrators.
To examine the medical, psychiatric, social work and forensic records of mothers referred for detailed psychiatric assessment from 1996 to 2009.
Twenty-eight consecutive individuals with a putative diagnosis of fabricated or induced illness were referred to the authors for detailed psychiatric assessment and recommendations about management (25 from family courts). We scrutinised all medical and psychiatric records and interviewed them, as well as informants.
In total, 16 (57%) had evidence of a current somatoform disorder, and factitious disorders (either past or current) were identified in 18 (64%): 11 participants had both somatoform and factitious disorders. Nine participants (32%) had non-epileptic attacks. We found evidence of pathological lying (pseudologia fantastica) in 17 (61%) of the participants; in some there were key links between early abusive experiences, the development of pathological lying and the eventual fabrication of illness in the child victim.
A chronic somatoform disorder or factitious disorder (or both) was detected in almost two-thirds of the participants. Over half of the mothers exhibited pathological lying, in some dating from adolescence, and this often continued into adult life eventually involving the child in a web of deceit and abuse. Psychiatrists whose work brings them into contact with women with chronic somatoform or factitious disorders, especially if there is evidence of lying from an early age, should always be alert to the impact of these illnesses on any dependent children.