MMPI-2 fake-bad scales: an attempted cross-validation of proposed cutting scores for outpatients

Minnesota Multiphasic Personality Inventory-2 (MMPI-2) results were compared in 118 psychiatric outpatients given standard instructions, instructions to exaggerate their problems, instructions to feign a disorder they did not have, or instructions to feign global psychological disturbance. The groups were comparable on demographic, occupational and diagnostic characteristics as well as intake MMPI-2 results. Experimental MMPI-2 results showed that clinical scales were generally elevated in the feigning groups, with only modest differences across dissimulating instruction sets. The feigning groups had reliably higher scores than controls on all overreporting indexes examined, although no significant differences between feigning groups were present for overreporting indexes. Classification rates using previously proposed cutting scores for outpatients on individual feigning indexes showed near perfect specificity, but low to at best moderate sensitivity. Multiple regression analyses indicated that Gough's (1954) Dissimulation Scale (Ds2) was most strongly related to feigning status, and no other feigning scale contributed a significant increment in predictive power once Ds2 was entered.