Development of an Infrequency-Psychopathology scale for the MMPI-A: the Fp-A Scale

Area of Science:

• Psychological assessment
• Clinical psychology
• Psychometrics

Background:

• The Minnesota Multiphasic Personality Inventory-Adolescent (MMPI-A) is a widely used tool for assessing psychopathology in adolescents.
• Existing validity scales, such as the F scale, aim to detect response biases, including faking bad.
• The Infrequency-Psychopathology scale, F(p), was developed for the MMPI-2 to improve the detection of exaggerated symptom reporting.

Purpose of the Study:

• To describe the development and initial validation of the Infrequency-Psychopathology scale, Fp-A, specifically for the MMPI-A.
• To evaluate the efficacy of the Fp-A scale in discriminating between genuine psychopathology and simulated overreporting.

Main Methods:

• Development of a 40-item Fp-A scale, mirroring the MMPI-2's F(p) scale.
• Initial validation of the Fp-A scale using data from MMPI-A administrations.
• Comparison of the Fp-A scale's performance against the standard F scale in identifying faking bad.

Main Results:

• The Fp-A scale demonstrated superiority over the F scale in discriminating between faking-bad and accurate reports of psychopathology.
• The improvement in discrimination provided by Fp-A over F was modest.
• The relative effectiveness was influenced by the MMPI-A's F scale performing better than the MMPI-2's F scale.

Conclusions:

• The Fp-A scale is a valuable addition for enhancing the detection of overreporting on the MMPI-A.
• Using Fp-A in conjunction with the F scale may improve the identification of exaggerated psychopathology.
• Further research may be warranted to fully explore the utility of Fp-A in clinical settings.