The Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) defines malingering as "intentional production of false or grossly exaggerated physical or psychological symptoms, motivated by external incentives..."

Exaggeration or faking of emotional problems is of concern to lawyers representing both plaintiffs and defendants. A plaintiff's attorney may wonder if the client's reported emotional disorder is genuine and, therefore, if the case has merit, especially if there are no other damages such as physical injuries. An attorney for a defendant may also wonder if the plaintiff's emotional damages are real since one responsibility of counsel for the defendant is to identify claims that are without merit. Questions about the credibility of emotional distress damages have been asked of me many times, by plaintiff's and defendant's counsel, when I have testified as an expert in personal injury trials.

How common is malingering? Some studies show that faking of psychological symptoms is quite rare. In one study, for example, Lees-Haley (1992) found that only 1 of 64 personal injury claimants scored in the significant range on two separate measures of exaggeration of mental symptoms. In another study by the same author, however, 96% of untrained volunteers were able to fake depression on the Beck Depression Inventory, a standard test for measuring depressive symptomatology.

Some instances of apparent malingering may actually be caused by genuine psychological problems. Individuals with a "personality disorder", a type of mental disorder which is pervasive and originates in adolescence or early adulthood, may appear dramatic and emotional in their demeanor. Price (1994) and other investigators theorized that individuals with a personality disorder might also produce dramatic or exaggerated results on measures of malingering. In an empirical study, they found significant correlations between measures of personality disorders and indicators of malingering. These results were interpreted to mean that some indicators of malingering might actually be effects of mental illness. Identification of chronic mental problems can be useful also because pre-trauma mental conditions can increase vulnerability to the effects of traumatic events.

The Minnesota Multiphasic Personality Inventory-2 (MMPI-2), a standard psychological test consisting of 567 true-false questions, appears to have considerable effectiveness when used as a measure of malingering. In particular, the MMPI's validity scales F and K have been studied for this purpose. The F (Infrequency) scale may be the most popular of the MMPI scales used in detection of malingering. High scores on the F scale are often obtained by individuals who are admitting to many symptoms or complaints that are typically not endorsed by the general population. Thus, a high F score may reflect genuine psychopathology or exaggeration of symptoms. Another potentially useful indicator of faking is the F-K score. Originally proposed by H.G. Gough in 1950, this index can be utilized to discriminate between "fake bad" and non-faked (valid) MMPI profiles. The F-K index has been studied with actual malingerers in pre-trial situations and has been found to be useful in distinguishing them from non-malingering subjects. More recently, unique combinations of MMPI test items have been assembled into new scales, such as Lee-Haley's Fake Bad Scale, and investigated specifically for the purpose of identification of faking of emotional disorders.

The question of malingering is of concern to lawyers for plaintiffs and defendants in personal injury, worker's compensation and disability cases in which plaintiffs are alleging emotional injuries. Comprehensive evaluation by a psychologist employing standard psychological tests such as the MMPI can be useful in identifying or ruling out malingering and can help to identify pre-trauma mental problems which could increase a client's vulnerability to the effects of stress.