The MMPI in neuropsychological assessment: a murky measure

The Minnesota Multiphasic Personality Inventory (MMPI) is commonly used in neuropsychological assessment in hope of ferreting out the presence of psychiatric disorders and "emotional factors". This paper discusses whether or not the MMPI can in fact do this intended task. The conclusion is that the MMPI is a poor measure of emotional adjustment and a poor aide to differential psychiatric diagnosis because the question pool is contaminated by questions that can be endorsed by neurologic and other medical patients for reasons other than emotional maladjustment or psychiatric disorder. Several MMPI scales may be elevated in a neurologic patient's profile simply because his/her symptoms are consistent with a neurologic disorder and are not necessarily a reflection of pathological adaptation or poor emotional adjustment. The safe assumptions to make in interpreting the MMPIs of neurologic patients are presented. The need to use a comprehensive assessment process to understand personality, psychological reaction, and psychiatric disorder is emphasized.