The role of depression severity in the cognitive functioning of elderly subjects with central nervous system disease.

OBJECTIVE

To examine the hypothesis that there is a causal relation between depression and cognitive dysfunction in patients with central nervous system (CNS) disease.

DESIGN

Retrospective analysis of a clinical database.

SETTING

Tertiary geriatric day hospital.

PATIENTS

Sixty-five patients with depression and CNS disease, and 201 patients with depression but without CNS disease.

OUTCOME MEASURES

Scores on the Hamilton Depression Rating Scale (Ham-D) and the Mattis Dementia Rating Scale (MDRS).

RESULTS

A logistic regression analysis using MDRS status as the dependent variable, and a number of clinical variables as the predictor variables, showed that, in patients with CNS disease, only the Ham-D score predicted MDRS status (R = -0.19, p = 0.02). Ham-D score even more strongly predicted scores on a frontal system subtest of the MDRS (R = -0.262, p = 0.005). Ham-D score did not predict MDRS status in patients without CNS disease. Mean Mini Mental State Examination scores for the group with CNS disease were 25.1 at admission and 26.1 at discharge (p < 0.001).

CONCLUSIONS

These findings suggest that depression contributes to frontal cognitive dysfunction in patients with CNS disease.