Differential diagnosis using the MMPI-2: Goldberg’s index revisited

BACKGROUND: The Minnesota Multiphasic Personality Inventory (MMPI-2) often supports clinical decision-making in complex diagnostic problems like differentiating neurosis from psychosis and psychosis from bipolar disorder. The MMPI Goldberg index, an arithmetical combination of five clinical scales, has been considered to provide a good estimate for discriminating between neurotic and psychotic profiles. Similarly, the MMPI-2 Personality Psychopathology Five (PSY-5) scales have been found to be useful in differentiating diagnostic categories. METHOD: This study evaluates these findings in a sample of psychiatric patients diagnosed with depressive, psychotic, or bipolar disorder using ANOVA and discriminant analysis. RESULTS: Results corroborate the validity of Goldberg's index and find MMPI-2 PSY-5 scale Disconstraint to significantly differentiate between psychotic and bipolar-I disorder. CONCLUSION: The MMPI-2 Goldberg index and PSY-5 scales can offer a useful contribution to the differential diagnosis of depressive, psychotic and bipolar disorder.