Effects of Psychopathology and Demographic Characteristics on MMPI-A Scale Scores

Using multiple linear regression analyses, we examined the effects of participant status for 3 demographic variables and the presence of psychopathology on variance in MMPI-A scale scores. The analyses were designed to measure the incremental contribution of demographic variables to scale variance beyond that explained by the presence of psychopathology. The validity and clinical scales were characterized by small amounts (< 10% incremental explained variance of influence by demographic variables. The F and BIZ scales were influenced most by demographic variables. With a single exception (BIZ scale), the set of demographic variables explained less than 10% of the variance in content-scale scores. No demographic variable influence was found for supplementary-scale scores. The results are discussed in light of other potential factors that might explain MMPI-A scale score variance.