Does antidepressant therapy improve cognition in elderly depressed patients?

Objectives. To analyze the effects of antidepressants on cognitive functioning in elderly depression. Methods. Data were pooled for elderly participants with major depression from two double-blind 12-week studies (n = 444) comparing sertraline to fluoxetine and to nortriptyline. A cognitive battery was performed pre-treatment and post-treatment that included the Shopping List Task (SLT), which quantifies short-term and long-tern memory storage and retrieval, and the Digit Symbol Substitution Test (DSST), which measures visual tracking, motor performance, and coding. Results. Older age, male gender, higher systolic blood pressure, and higher illness severity were associated with lower performance on specific cognitive measures at baseline. For the entire group, improved depression and a lower anticholinereic side effect (dry mouth and constipation) severity were associated with statistically significant improvement in the SLT and DSST. The correlations between improvements in depression and improvement in tested cognitive function were highest for sertraline followed by nortriptyline and then fluoxetine. Conclusions. Acute improvement in depression is associated with cognitive improvement as measured by the SLT and DSST. Prospective studies are warranted to study the effects of potential differences among antidepressant therapies on long-term cognitive outcomes in geriatric depression.