Serum levels of TDP-43 in late-life patients with depressive episode

Abstract

Background: Recent reports have suggested a relationship between affective disorder including depression and bipolar disorder (BP) and frontotemporal dementia (FTD). TAR DNA binding protein (TDP) -43 is a protein found in the brain and peripheral fluid of patients with FTD. To examine a possible association between affective disorders and FTD, serum levels of TDP-43 were evaluated in late-life patients with major depressive episode (MDE).

Methods: The subjects were 74 late-life (≥50 years old) inpatients with DSM-IV or -5 MDE (58 had major depressive disorders and 16 had BP) and 58 healthy subjects. Patients were recruited from Juntendo Koshigaya Hospital, Saitama, Japan, between January 2005 and May 2017. Serum TDP-43 levels were measured using an ELISA kit.

Results: Serum levels of TDP-43 were significantly higher in the MDE group than the control group independent of age and sex.

Limitations: All patients were on antidepressant medication.

Conclusions: Our finding suggests that some depressive patients may be in a prodromal stage of FTD or very-early stage of FTD comorbid with depression.