Development and validation of the malingering discriminant function index (M-DFI) for the Minnesota Multiphasic Personality Inventory - 2 (MMPI-2)
By: by Jason R. Bacchiochi.
Published: 2005
Language: eng
Number of pages: 108
Subjects: Minnesota Multiphasic Personality Inventory.; Malingering -- Diagnosis.
Description: The Minnesota Multiphasic Personality Inventory - 2 (MMPI-2; Butcher, Graham, Ben-Porath, Tellegan, & Dahlstrom, 2001), the most widely used instrument for the assessment of personality and psychopathology (Camara, Nathan, Puente, 2000), contains a number of "validity" scales designed to assess malingering. Although these traditional validity scales (i.e. F, FB, and FP) have proven effective, there are growing bodies of evidence indicating that: (1) when psychological assessments take place within a forensic or psychological disability context, some clients may be informed about these validity scales (Wetter & Corrigan, 1995; Youngjohn, 1995) and (2) these traditional validity scales are less effective when potential malingerers are instructed (or "coached") about how these scales work (Bury & Bagby, 2002; Lamb, Berry, Wetter, & Baer, 1994; Rogers, Bagby, & Chakraborty, 1993; Storm & Graham, 2000). The goal of the current investigation was to develop a validity index for the MMPI-2 that would be impervious to the effects of "coaching," including memorization of validity scale items. Using an actuarial-based scale-development procedure, a malingering index was constructed using clinical and content scales---the Malingering Discriminant Function Index (M-DFI). Phase I of this investigation employed discriminant function analysis (DFA) to derive the M-DFI . The derivation DFA identified 17 scales (four clinical, two content, and 11 content component) that were able to significantly distinguish a group of bona fide psychiatric patients and groups of validity scale coached research participants that were instructed to feign psychopathology. These 17 scales formed the basis of the M-DFI. Two subsequent validity studies were performed, which revealed the predictive validity and the incremental validity of the M-DFI relative to the standard validity scales  F, FB, and FP. Compared to these standard validity scales, the M-DFI showed little attentuation in predictive capacity in experimental studies in which research participants were instructed (coached) on how to feign mental illness when completing the  MMPI-2. Although replication is needed, the M-DFI may prove to be a useful addition to the standard validity scales on the  MMPI-2 to detect malingering.
Notes: Thesis (Ph.D.)--University of Toronto, 2005.

Includes bibliographical references (leaves 86-96)