An evaluation of the usefulness of the MMPI-2 F(p) scale

The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) F(p) scale was d eveloped by Arbisi and Ben-Porath (1995) by identification of 27 items endo rsed by fewer than 20% of individuals in both normal and psychiatric sample s. The F(p) scale was designed for applications in settings characterized b y high base rates of serious psychopathology, such as psychiatric inpatient units, and is proposed as a useful scale in discriminating overreported pr otocols from those produced by patients with serious psychopathology. In th is study we investigated the characteristics of this scale in a sample of 6 17 psychiatric inpatients who responded to the MMPI-2 under standard condit ions, and 203 overreported protocols derived in research studies conducted with normal adult participants instructed to simulate various forms of seri ous psychopathology. Results of this study are consistent with prior report s of a relatively low frequency of item endorsement for F(p) scale items in psychiatric samples, and intercorrelations between the F(p) scale and the MMPI-2 basic clinical scales in clinical samples that are generally lower t han those produced between either F or Fb and the basic clinical scales. Ho wever, this intercorrelational pattern between F(p) and the MMPI-2 basic sc ales was not as consistent for the overreported sample. Additionally, the F (p) scale appears to be effective in discriminating overreported from accur ate MMPI-2 protocols, with some evidence that the optimal cutting scores fo r this and other MMPI-2 infrequency scales may differ as a function of gend er. Finally, these findings do not show clear evidence of improved group pr ediction derived from the use of the F(p) scale in contrast to results obta inable through the use of the MMPI-2 F scale.