Consumption of psychotropic medication in the elderly: a re-evaluation of its effect on cognitive performance

There have been few general population studies of the effects of psychotropic treatment on cognitive functioning in the elderly. Current evidence based on studies with numerous procedural shortenings supports the notion of the detrimental effect.

To examine changes in a wide range of specific cognitive abilities across time in a general population sample in order to establish a relationship between psychotropic drug use and cognitive performance, and to estimate to what extent such cognitive changes may be attributable to psychotropic use or other factors, notably age and co-morbidity.

We analysed the data from the Eugeria longitudinal study of cerebral ageing. Three hundred and seventy two subjects (263 female and 109 male) were visited at their place of residence and given a computerized cognitive examination. Depressive symptomatology and depressive episodes were defined according to ICD-9 criterias and medication use were established. Four categories of psychotropic consumers was differentiated. Using a logistic regression model, comparisons were made between consumers and non-consumers.

A significant positive effect in chronic consumers was found on tests of secondary memory (delayed verbal recall: Odds Ratio (OR)=1.22; 95% Confidence Intervals (CI) [1.04-1.43]; p=0.013) and this effect is principally attributable to antidepressants with significant effects being shown for both verbal (OR=1.59; 95%CI [1.18-2.14]; p=0.002) and visual recall (OR=1.51; 95%CI [1.05-2.16]; p=0.025). No effect is found for benzodiazepines.

Contrary to the common belief that psychotropic drug use has a detrimental effect on cognitive function of elderly people, even long term use is seen to be benign. We attest to the positive effects of antidepressant therapy on secondary memory.