Robinson D G, Spiker D G
J Affect Disord. 1985 Jul;9(1):79-83. doi: 10.1016/0165-0327(85)90013-8.
Fifty-two unipolar delusional depressives were matched to 52 unipolar nondelusional depressives on the basis of sex, age at index episode of depression and age at first episode of depression. In a one year follow-up after discharge from inpatient treatment, the delusional depressives had a poorer clinical course than the nondelusional depressives as manifested by significantly higher rates both of major depression or delusions lasting longer than 9 months and of being in a major depressive episode at the end of the follow-up period.