A taxometric analysis of the MMPI-2 Depression scales

The MMPI (Hathaway & McKinley, 1943) and MMPI-2 (Butcher et al., 2001) have long been used as measures of psychopathology. Both clinicians and researchers have noted the widespread existence of negative affectivity on the MMPI and MMPI-2 that may elevate scale scores and eclipse the tests' ability to differentiate depression from other clinical disorders. Using taxometric analyses, in this study we sought to test directly whether the MMPI-2 depression scales could differentiate patients with depressive symptoms from patients with other disorders. A large psychiatric sample (N = 2,000) was utilized and analyses were run separately for men and women. Taxometric analyses did not find a MMPI-2 Depression scale cut point that categorizes patients with depressive symptoms from other patients. Rather, these findings support previous studies finding an underlying dimensionality of depression. We discuss implications for MMPI-2 scale use and depression nosology in light of these findings.