“There were no real demons, no talking dogs, no satanic henchmen. I made it all up via my wild imagination so as to find some form of justification for my criminal acts against society” [“Son of Sam” serial killer David Berkowitz].

Deception is a frequent behaviour that occurs in day to day life. In the setting of the doctor-patient or lawyer-client relationship, self-disclosure is rarely complete and accurate and individuals are selective about how much they share with others.

Malingering has been defined by the American Psychiatric Association as “the intentional production of false or grossly exaggerated physical or psychological symptoms, motivated by external incentives”. Malingering itself is not considered to be a form of mental illness or psychopathology but although it can occur concurrently with mental illness.

According to DSM-IV-TR, malingering should be strongly suspected if any combination of the following factors is noted to be present: (1) medico-legal context of presentation; (2) marked discrepancy between the person’s claimed stress or disability and the objective findings; (3) lack of cooperation during the diagnostic evaluation and in complying with the prescribed treatment regimen; and (4) the presence in the patient of antisocial personality disorder (ASPD). However, criticism has been levelled against this criteria and some have suggested that they result in a misclassification rate of over 80%.

The distinction between malingering, factitious presentations and feigning is not always well understood. In contrast to malingering, factitious presentations are characterised by the intentional production or feigning of symptoms that is motivated by the desire to assume a “sick role”. Feigning is the deliberate fabrication or gross exaggeration of psychological or physical symptoms without any assumptions about its goals.

Malingering is important from a clinical and medico-legal perspective. In my own clinical practice, it is not uncommon to encounter patients who feign symptoms in order to obtain prescribed drugs or government disability benefits. In my medico-legal practice, I sometimes encounter individuals who feign psychological symptoms in order to avoid responsibility or punishment; escaping criminal liability is a common motivation to malinger. In civil cases, it is not unusual to encounter individuals who exaggerate symptoms for financial reward.

Since it is unusual for people to admit they are faking symptoms, detecting malingering can be challenging, particularly for clinicians whose traditional relationship with patients is based on the assumption that a patient is in genuine need of assessment and treatment.

The consequences of failing to detect malingering can be the wastage of vital resources to the detriment of those who have genuine mental illness. In the medico-legal context, confidence in justice is eroded when individuals who malinger escape criminal liability or receive financial rewards.

The clinical assessment of malingering is usually approached through (1) Clinical interview, (2) Collateral information and (3) Use of one or more validated instruments (e.g. the Structured Interview of Reported Symptoms [SIRS].

One of the leading authorities on malingering, Richard Rogers, suggests that the clinical interview can unearth an unusually high number of symptoms that are rare or improbable. Rare symptoms are valid symptoms that are infrequently reported. Malingerers will sometimes endorse improbable symptoms although improbable symptoms are almost never reported even in severely disturbed patients. It is also important that the clinician pays close attention to evidence of inconsistency or contradiction when evaluating a suspected malingerer.

The study of collateral information including review of medical records, interviews with informants (e.g. relatives, other clinicians) and police reports and witness statements can uncover information that supports or refutes the self-reported symptoms of the individual being evaluated.

In the medico-legal setting, psychometric evaluations using one or more validated instruments can provide a more objective measure of inconsistencies or contradictions in an individual’s presentation. There are a number of psychological instruments and structured clinical interviews that have been developed specifically for evaluating malingering. For example, the Structured Interview of Reported Symptoms is a structured clinical interview that may be used to differentiate malingered schizophrenia and mood dis- orders from genuine presentations.

Finally, while some clinicians and legal practitioners consider that malingering is very rare, large-scale surveys of more than 500 experts suggest that malingering is not rare in either the clinical or forensic setting. It is therefore important that malingering should be systematically assessed and evaluated when the outcome of an evaluation has important consequences.