[Assessment of simulation and dissimulation in the MMPI-2 test profiles]

The aim of this study is to identify the criteria which would allow a differentiation between the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) profiles, obtained from patients who present with problems of minimization of attitude (dissembling) who have shown a minimization of their problems; from patients who answered in a spontaneous and genuine fashion.

Six hundred and fifty five MMPI profiles of outpatients of the Clinical Psychology Unit, University Hospital, Sapienza University of Rome. Patients were subdivided into two groups, based on the reason for attending: those who submitted voluntarily to a psychodiagnostic assessment and those who were assessed by request of an outside authority, e.g., in the case of those whose driving license was suspended. It has hypothesized that the latter group would not present with problems which would preclude obtaining the benefits required. The variables analyzed were the clinical scale and the validity scale MMPI-2, index F-K and the Ds scale of Gough. On the basis of the values of the F-K index and Ds scale, the patients were reclassified into three simulation categories: spontaneous registration; defended and doubtful's.

All indexes, validity scales and clinical scales of the standard profile were found to have significant differences between the "dissimulation" and "normal" groups. Sensibility and specificity of profile classification was according to both indexes 76%.

Current evidence indicates that simulation of pathology is identifiable in MMPI-2 profiles. Our data demonstrate that it is possible to identify case of defensive minimization. These results confirm the hypothesis that simulation is a dimensional characteristic of MMPI which can reach extreme values in both ways: worsening of slight problems or suppression of existing problems.