Does late onset depression predispose to dementia? A retrospective, case-controlled study.

BACKGROUND

Recent research suggests that there are clinical and biologic characteristics typical of late onset depression (LOD). Furthermore, evidence has been put forward that LOD may be a prodrome of dementia.

OBJECTIVE

This study aims to assess the association between LOD and the development of dementia.

SETTING

The study was conducted in a tertiary care, university-affiliated mental health center providing services for an urban catchment population of 800,000 subjects.

METHOD: A retrospective, case-controlled study was used.

RESULTS

Fifty-one patients with LOD who developed dementia at least 1 year after diagnosis of LOD were defined as the index group: 18 males and 33 females, with a mean age of 75.4 ± 9.2 years. These were compared with 51 patients with LOD who did not develop dementia during a 10-year follow-up period. Dementia types were as follows: 73% Alzheimer disease, 24% vascular and mixed dementia, and 3% Parkinson dementia. Patients with LOD who developed dementia were significantly characterized by having longer hospitalization for their first depressive episode (P = .048), having a family history of dementia (P = .022), and having been exposed to the Holocaust as young adults (P = .013).

CONCLUSIONS

Patients with a history of significant traumatic experience in early life and a prolonged onset of depression may be at particular risk of developing dementia. This issue requires further long-term prospective studies.