The Efficiency of MMPI-2 Validity Scales in Detecting Malingering of Mixed Anxiety-Depressive Disorder

IntroductionPersonality inventories are often administered in psychodiagnostic evaluation due to the fact that they are relatively economical, simple to administer and can be scored completely objectively. One of the problems in the use of these inventories (as with the use of the interview) is the tendency of some persons to present themselves better or worse than they actually are. Some situations, child custody cases or professional selection, for example, may induce a person to present themselves in a more positive light and to avoid those responses which may indicate psychopathology. In other situations, some persons may, consciously, others unconsciously, present themselves in a more negative light than is true of them. Highly anxious persons with regressive function patterns, experiencing significant anxiety and other negative feelings may unconsciously overreport symptoms, using this method to seek help [1 -2]. However, in situations where it is possible to gain a certain advantage (e.g., financial benefits or avoiding responsibility in forensic processing) it can be presumed that the person is highly motivated to display various symptoms and that they are aware of this. In cases when a person displays symptoms they are not experiencing, overreport existing symptoms, or assigns the symptoms to a cause which is known not to be related to the symptoms, we can use the term malingering [3]. Persons who malinger symptoms often report symptoms which are rare in clinical samples, improbable symptoms (extreme variants of rare symptoms), symptoms which rarely occur together, a large number of symptoms they consider to be severe and symptoms they consider to be indicative of psychological disorders. However, it is clear that the manner of malingering a psychological disorder will depend on the person's knowledge and the stereotypes of persons about the disorder [4]. In comparison with data collected in the interview, where the assessment of malingering is based on the clinician's judgment, many self-report measures have a distinct advantage because of the incorporated validity scales which aid in determining response style. The Minnesota Multiphasic Personality Inventory-2 (MMPI-2 [5-6]) includes three Infrequency scales [F (Infrequency) Scale, Fb (Back Infrequency) Scale and the Infrequency - Psychopathology (Fp) Scale] which are used to determine the tendency of providing rare responses or listing rare and improbable symptoms. Apart from these scales, the F-K index (Gough Dissimulation Index) was developed for the MMPI-2, with additional scales for determining a persons' tendencies toward defensive responding, minimization and denying psychopathology [12]. The Infrequency Scale F and the Back Infrequency Scale Fb include responses which persons from the normative group (healthy population) rarely endorse in the direction in which they are scored. The consequence of this is the fact that, not only the malingerers, but also persons with severe disorders such as schizophrenia, depression, posttraumatic stress disorder, personality disorders and organic brain damage may have elevated results [13-17]. The Infrequency - Psychopathology Scale (Fp), constructed for the purpose of surpassing the deficiencies of the F and Fb scales, includes responses rarely endorsed by healthy persons and those with clinical disorders in the direction they are scored. This scale aids in the explanation of elevated scores on the F and Fb scales, that is, in differentiating cases where elevated scores on the F and Fb scales are the result of malingering from those where the scores are the result of severe psychopathology.There are numerous studies which have confirmed the efficiency of the validity scales in differentiating the MMPI-2 profiles of persons instructed to malinger disorders and the profiles of actual patients. The studies involved a group which was given information on the symptoms and/or information on validity scales, and a group from which this information was withheld [18-25]. …