Evidence that depression rating scales primarily measure a social undesirability response set.

Many popular methods of measuring depression have not been adequately validated for discriminant validity from social desirability. In a study of 26 patients, 14 with secondary depression, and 12 nondepressives, it was shown that the commonly used Beck Depression Inventory and MMPI Depression scale and the Carroll self-administering version of the Hamilton scales correlate as highly with social undesirability as with each other. Social desirability ratings of item alternatives on the Beck and Hamilton scales by 12 normal students showed the depth of depression to be significantly related to social undesirability response scores. The difficulty of distinguishing depression and social undesirability response set was discussed and it was suggested that "low self-esteem" may be all that is measured by the rating scales used in this study.