Effects of commonly prescribed drugs on cognition and mild cognitive impairment in healthy elderly people.

BACKGROUND: Chronic drug intake has been associated with negative and positive cognitive effects in elderly people, although subjacent conditions may be confounding factors. AIM: To study the effects on cognitive performance of commonly prescribed medications in a cohort of cognitively normal older adults. METHODS: Medication intake was recorded during two years in 1087 individuals 70-85 years old, without neurological or psychiatric conditions. The influence of every drug, drug family and therapeutic group on six cognitive scores and on the conversion to mild cognitive impairment over two years was ascertained by cross-sectional and longitudinal analyses controlling for demographic and clinical variables. RESULTS: Small effects of several drugs on information processing were found in cross-sectional analyses but only confirmed for a positive effect of vitamin D in case-control analyses. Longitudinal analyses showed no drug effects on the cognitive slopes. Several hypotensive drugs reduced, whereas bromazepam and glucose lowering drugs increased, the conversion rate to mild cognitive impairment with very small effects (R2=0.3-1%). CONCLUSIONS: Cognitively healthy elderly individuals show minimal negative effects on information processing associated with chronic intake of some drugs probably related to the subjacent condition. Some drugs slightly affect the rate of conversion to mild cognitive impairment. Positive effects of vitamin D, chondroitin, atorvastatin and antihypertensive drugs, and negative effects of antidepressants and benzodiazepines, should be further explored in studies with longer follow-up.

Clinical Relevance of Specific Cognitive Complaints in Determining Mild Cognitive Impairment from Cognitively Normal States in a Study of Healthy Elderly Controls.

Introduction: Subjective memory complaints (SMC) in the elderly have been suggested as an early sign of dementia. This study aims at investigating whether specific cognitive complaints are more useful than others to discriminate Mild Cognitive Impairment (MCI) by examining the dimensional structure of the Everyday Memory Questionnaire (EMQ). Materials and Methods: A sample of community-dwelling elderly individuals was recruited (766 controls and 78 MCI). The EMQ was administered to measure self-perception of cognitive complaints. All participants also underwent a comprehensive clinical and neuropsychological battery. Combined exploratory factor analysis (EFA) and Item Response Theory (IRT) were performed to identify the underlying structure of the EMQ. Furthermore, logistic regression analyses were conducted to study whether single cognitive complaints were able to predict MCI. Results: A suitable five-factor solution was found. Each factor focused on a different cognitive domain. Interestingly, just three of them, namely Forgetfulness of Immediate Information (FII), Executive Functions (EF) and Prospective Memory (PM) proved to be effective in distinguishing between cognitively healthy individuals and MCI. Based on these results we propose a shortened EMQ version comprising 10 items (EMQ-10). Discussion: Not all cognitive complaints have the same clinical relevance. Only subjective complaints on specific cognitive domains are able to discriminate MCI. We encourage clinicians to use the EMQ-10 as a useful tool to quantify and monitor the progression of individuals who report cognitive complaints.