Introduction

Mental health professionals rely primarily on a patient’s self-report to diagnosis and develop treatment interventions. The reliance on self-report is often effective when a therapeutic alliance exists between the patient and the professional, with the shared goal revolving around the alleviation of mental health suffering and achievement of optimal functioning. However, there are other clinical evaluations in which the evaluee’s self-interests are not necessarily parallel with the professional’s task. As an illustrative example, let us consider the most commonly requested forensic evaluation referral: competency to stand trial. In this instance, the hypothetical case involves the court ordering an evaluation of Mr. Jones, who is charged with the murder of his wife. Like many defendants, Mr. Jones has a goal of receiving the least serious consequences possible or avoiding prosecution all together. In an effort to achieve his goal, the defendant may attempt to feign or exaggerate mental health symptoms in order to avoid criminal prosecution. In contrast, the clinician’s goal is to provide an accurate diagnostic impression and professional opinion regarding the defendant’s capacity to proceed to trial, both of which may be detrimental to the defendant.

Likewise, consider a situation in which Ms. Smith is charged with murdering her husband, after which she is referred to a mental health professional to undergo an evaluation of her mental state at the time of the crime. The defendant is claiming she was acutely psychotic at the time of the alleged offense. After interviewing the defendant and conducting extensive psychological testing, the clinician opined Ms. Smith is malingering in order to avoid criminal prosecution. Ms. Smith is subsequently tried and found both guilty and criminally responsible for killing her husband, at which point she is sent to prison and not provided mental health services. As both of these scenarios illustrate, a clinician’s ability to successful differentiate between people with a bona fide mental illness versus people who are exaggerating symptoms of mental illness is extremely important and has a variety of long-term consequences.

The goals of this chapter are relatively straightforward:

• Discuss and critically evaluate current conceptualizations of malingering.
  
• Provide general information on malingering models and note how models can and should inform clinical practice.
  
• Introduce the idea of an additive approach to the assessment of malingering, during which a clinician uses a number of clinical tools to evaluate malingering.
  
• Select appropriate methodologies to detect malingering, with an emphasis on forensic populations.

Current conceptualization of malingering

According to the Diagnostic and Statistical Manual of Mental Disorders, 5th ed. (DSM-5) [1], malingering involves intentionally fabricating or grossly exaggerating symptoms in an effort to obtain external incentives or some type of secondary gain. The DSM-5 provides examples of external incentives, including: financial compensation, avoiding work, avoiding criminal prosecution, and obtaining drugs. The DSM-5 and its earlier counterparts suggest that malingering should be suspected if two or more of the following are present: medicolegal situations, a large discrepancy between the person’s claimed symptoms and objective data, a lack of cooperation with evaluation and treatment, and the presence of antisocial personality disorder.

Although the DSM-5 and its earlier editions are the most commonly used resource for making mental health diagnoses, a large number of conceptual weaknesses and practical concerns have been cited related to using this resource to diagnosis malingering [2]. First, scholars have argued the DSM criteria for malingering have an implicit judgment of “badness” relying on characterological traits (i.e., antisocial personality disorder), which provide little explanatory power concerning the accurate diagnosis of malingering. The DSM relies on contextual variables (medicolegal evaluations) and interpersonal variables (uncooperativeness during the evaluation), all of which are highly subjective, and none having significant empirical support [3]. Take the proposed connection between antisocial personality disorder (APD) and malingering. In a recent study conducted by Pierson, Rosenfeld, Green, and Belfi [4], forensic patients with APD were no more likely to be suspected of malingering by clinicians or to exceed acceptable cutoff scores on the Structured Interview of Reported Symptoms [5] (SIRS) than patients not diagnosed with APD. Additionally, research has consistently failed to support the connection between a medicolegal evaluation and malingering, which is especially evident when considering the relatively large discrepancy in base rates of malingering across studies of forensic evaluations [6, 7].

Moreover, another DSM index suggests that mental health professionals consider malingering when an individual is uncooperative with treatment. Using this criterion, almost all patients involuntarily committed to a mental health facility would fall under the rubric of suspicion, regardless of the underlying reason for their admission. This would include any patient admitted due to a severe suicide attempt as well as the patient with a documented long-standing mental health history who is experiencing complications from medicine interactions. Lastly, the DSM directs professionals to consider malingering whenever a large discrepancy exists between clinical distress and objective findings. Despite this proposition the DSM falls short on several key aspects including providing counsel on the directionality of this discrepancy, leaving professionals to rely on clinical judgment, and test results that by their very nature are often contradictory.

DSM criteria treat malingering as taxonic, leaving little room for clinicians to rely on empirically validated approaches. In contrast to the DSM, researchers, backed by data, have argued that malingering is a dimensional (exaggeration of symptoms on a continuum) rather than categorical (malingerer or honest dichotomy) variable [8]. Resnik [9] suggested the individuals may present with three types of malingering: (1) “pure malingering” (i.e., a complete fabrication of symptoms), (2) “partial malingering” (i.e., exaggeration of actual symptoms or reporting past symptoms as present currently), and (3) “false imputation” (i.e., deliberately linking symptoms to compensable events). Another fallacy unaddressed by DSM criteria is the assumption that many will feign indiscriminately and in every situation. Such an approach is not supported by the literature [2]. Instead, extant research points to general independence among types of malingering (i.e., cognitive, psychiatric, and physical [10]). In other words, most individuals who malinger do so with a specific set of symptoms they perceive will provide them the greatest benefit given the current situation. As such, clinicians should not assume “once a malingerer, always a malingerer,” because each situation warrants its own investigation into the validity of the symptom presentation.

In addition to conceptual concerns about the use of the DSM in diagnosing malingering, there are a number of practical concerns as well. One practical difficultly clinicians face in assessing and ultimately diagnosing malingering is the absence of any instrument, psychological or other, that can accurately identify a person’s motivation for fabricating mental health symptoms, making it nearly impossible to differentiate those who are malingering (externally motivated to exaggerate) from those with factious disorder or somatoform disorder (internally motivated to exaggerate in order to assume the sick role). Rogers and Vitacco [11] argued that since no test can measure motivation, mental health professionals are forced to speculate about whether a patient’s motivation to feign is intrinsic or extrinsic based on self-report and clinical judgment and to render a diagnosis accordingly. Another practical issue identified by Berry and Nelson [2] is that the DSM description of malingering has barely changed in over three decades, although research in this area has continued to advance at a rapid pace. Lastly, the practical utility of the conditions identified in the DSM as potentially indicative of malingering (i.e., medicolegal situations, lack of cooperation) has also been called into question. Rogers [3, 11] used these criteria to differentiate malingerers from non-malingerers and reported correct classification rates of only 20 percent.

What can be gleamed from the previous paragraphs is a need for refinement in the diagnostic criteria for malingering. All told, findings suggest that criteria outlined by the DSM for malingering are more inaccurate than accurate with minimal validity.

Alternative models of malingering

The utility of the DSM-5 diagnostic criteria for malingering is of questionable; however, even though it lacks empirical backing many clinicians continue to exclusively rely on these criteria when rendering a diagnosis of malingering. This reliance on unvalidated diagnostic criteria may at least partially explain why prevalence estimates of malingering vary widely across and within similar settings. For example, malingering prevalence rates in forensic cases range from 15 to 18 percent [7, 12], while studies conducted in forensic-psychiatric hospital settings have varied rates from less than 10 percent [13] to more than 25 percent [14–16].

In an effort to rectify some of the aforementioned criticisms of the DSM’s conceptualization of malingering, Rogers proposed the adaptational model of malingering [3]. The model includes three ideas: (1) a person perceives the evaluation/treatment as involuntary or adversarial, (2) the person perceives that he or she has either something to lose from being honest or something to gain from malingering, and (3) the person does not perceive a more effective means to achieve the desired goal [17]. This model provides testable constructs without imposing morality or judgment, and accounts for situational aspects of malingering. From that aspect, the model is consistent with decision theory, in which choices made under conditions of uncertainty are based on expected utility and likelihood of several courses of action [18].

Similarly, Slick, Sherman, and Iverson proposed a set of criteria for malingered neurocognitive dysfunction: (1) presence of substantial external incentive, (2) evidence from neuropsychological testing (i.e., performance below chance or what would be expected of the examinee), (3) evidence from self-report (i.e., self-reported symptoms are not consistent with behavioral observations), and (4) criteria 2 and 3 are not fully accounted for by psychiatric, neurological, or developmental factors [19]. The model proposed by Slick and colleagues provides testable hypotheses, which again is in contrast to the largely subjective criteria offered by the DSM.