MMPI-2 Symptom Validity (FBS) Scale: Psychometric Characteristics and Limitations in a Veterans Affairs Neuropsychological Setting

Abstract

The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) Symptom Validity (Fake Bad Scale [FBS]) Scale is widely used to assist in determining noncredible symptom reporting, despite a paucity of detailed research regarding its itemmetric characteristics. Originally designed for use in civil litigation, the FBS is often used in a variety of clinical settings. The present study explored its fundamental psychometric characteristics in a sample of 303 patients who were consecutively referred for a comprehensive examination in a Veterans Affairs (VA) neuropsychology clinic. FBS internal consistency (reliability) was .77. Its underlying factor structure consisted of three unitary dimensions (Tiredness/Distractibility, Stomach/Head Discomfort, and Claimed Virtue of Self/Others) accounting for 28.5% of the total variance. The FBS's internal structure showed factoral discordance, as Claimed Virtue was negatively related to most of the FBS and to its somatic complaint components. Scores on this 12-item FBS component reflected a denial of socially undesirable attitudes and behaviors (Antisocial Practices Scale) that is commonly expressed by the 1,138 males in the MMPI-2 normative sample. These 12 items significantly reduced FBS reliability, introducing systematic error variance. In this VA neuropsychological referral setting, scores on the FBS have ambiguous meaning because of its structural discordance.

Understanding forensic psychiatry in healthcare practices and collaboration between legal nurse consultants and physicians

“…Clinicians conducting forensic work rely on a variety of standard assessment measurements and rating scales. Some of these include the Minnesota Multiphasic Personality Inventory-2, 5 the Clinician-Administered PTSD Scale-Diagnostic version, 6 cognitive screenings, 7 and the Becks-Depression Inventory. 8 These help to determine diagnosis, evaluate competency and therefore pass opinion on criminal liability.…”

Neuropsychological assessment.

“…Some tests include item statements that represent unrealistic symptoms, such as "I sometimes vomit at the sight of stripes." In contrast to this approach to item selection, some widely used measures (e.g., the Fake Bad Scale, also known as the Symptom Validity Scale, of the MMPI-2 and MMPI-2-Restructured Form) are inherently flawed because they include many statements that are endorsed by more than 40% of the normal population (Gass & Odland, 2014;Gass, Williams, Cumella, Butcher, & Kally, 2010). Such statements include a denial of enjoying a sexually satisfying life.…”