Factor structure of the MMPI-168 in male narcotic addicts.

Factor analyses of abbreviated clinical and validating scales derived from the MMPI-168 yielded essentially the same solutions reported for full-length versions of the inventory. However, previously derived item-level factor scales did not emerge as distinct factors. Although the factor structures associated with black and white narcotic addict samples (N = 460) were highly similar, significant mean differences between the racial groups on many of the scales suggested the presence of greater psychopathology among white addicts.