Memantine Plus Es-citalopram in Elderly Depressed Patients With Cognitive Impairment

Study Summary

Alzheimer's disease (AD), the most common dementing disorder of later life, is a major cause of disability and death in the elderly. Although a number of theoretical causes exist, the etiology of AD is still unknown. Consequently, the focus of treatments has been palliative, designed to ameliorate AD symptoms. Recent efforts, however, have revealed some surprising data suggesting that cholinesterase inhibitors (AchEIs), used over the last decade, and recently released memantine (an N-methyl-D-aspartate (NMDA) receptor antagonist), may confer protection to neurons. Thus, they may offer a slowing of cognitive decline and/or improvement in behavioral symptoms associated with memory impairment. Over the last decade, it has been well documented that mild cognitive impairment (MCI) increases the risk of conversion to AD and that coincident depression and MCI (Dep-MCI) further increases the risk 2 to 3 fold. The primary focus of this line of investigation is to treat the very high risk to dement patient population with Dep-MCI, before they develop AD, in the hopes of delaying AD onset. Memantine had not been studied in DEP-MCI patients. Since treatment of these patients with combined antidepressant and AChEIs has been associated with cognitive improvement in pilot studies, we explore whether treatment of DEP-MCI with memantine in addition to antidepressant treatment would benefit cognitive performance and lead to a low rate of conversion to dementia. We evaluate the cognitive and antidepressant benefit of combined open-label es-citalopram and memantine treatment over 48 weeks in a DEP-CI sample.

Primary Outcome

Change in Selective Reminding Test-Total Immediate Recall (SRT-IR) scores from baseline to Week 48: Measures word recall (maximum 12 words per trial, across 6 trials). Maximum total recall score across 6 trials is 72; minimum recall is 0 across 6 trials. The higher the raw score, the better the patient did at recalling the target words. The unit of measure is the raw score, or the sum of the number of words recalled across all 6 trials.

Interventions

• DRUG Memantine
• DRUG es-citalopram