C.S. Newmark, J. Konanc, C. Aponte, B. Gard
Journal of Clinical Psychology
1977 Jul: 33(3):741-3.

Abstract:
An attempt was made to compare admission MMPI profiles of a matched sample of psychiatric inpatients over a 15-20 year period. For both makes and females, significant decreases in MMPI indices of psychopathology occurred. Possible reasons for this decrease are presented.