Comparing diagnostic validity of the TAT and a new picture projective test.

Diagnostic validity of the TAT and a new picture projective test, the PPT, were compared for normal, depressed, and psychotic subjects. Generally, the PPT elicited more positive emotional tone, more activity, and fewer thematic deviations than the TAT. The PPT and TAT were essentially equal in the capacity to discriminate between stories of normal and depressed subjects; however, the PPT was superior in differentiating psychotics from normals and depressives. On the PPT, depressives told stories with gloomier emotional tone and psychotics made more perceptual distortions, thematic and interpretive deviations. None of these differences were apparent on the TAT. The PPT pictures seem to have more diagnostic validity than the TAT stimuli.