Temporal variation of validity of self-rating questionnaires: improved validity of repeated use of Zung's Self-Rating Depression Scale among women during the perinatal period

Kitamura T, Sugawara M, Shima S, Toda MA. Temporal variation of validity of self-rating questionnaires: improved validity of repeated use of Zung's Self-Rating Depression Scale among women during the perinatal period. J Psychosom Obstet Gynaecol. 1999; 20(2): 112-7.