Cognitive Effects of Memantine in Postmenopausal Women at Risk of Dementia: a Pilot Study

Memantine is a well-tolerated moderate-affinity, uncompetitive, voltage-dependent NMDA receptor antagonist that is shown to improve cognition and behavior in mild to moderate and moderate to severe Alzheimer's disease (AD). More recent, albeit limited, evidence also shows benefits of memantine treatment in a host of other disorders such as vascular dementia, pervasive developmental disorders, depression and frontal temporal dementia case studies. However, no studies to date have sought to determine if memantine has potential as a primary prevention for AD.

Incidence rates of AD are expected to more than double from 1995 to the year 2050 as baby boomers age and it is predicted that this substantial increase will create a devastating global burden. At present, there are no treatments that prevent or 'cure' AD; however, treatments that delay the onset of dementia could provide significant reductions in incident rates. Epidemiological studies estimate that an increase in cognitive reserve of only 5% would substantially reduce the incidence rate of AD by one-third; therefore, interventions that precede the manifestation of AD would be most beneficial.

Over the past several years, research on dementia focused on determining the factors that were involved in the progression from mild cognitive impairment to dementia. Clearly, when interventions can be introduced before any cognitive decline is evident the better the chance of reducing incidence dementia. Few studies have investigated risk factors for AD other than genetic vulnerability and primary prevention studies are essentially non-existent. Known and putative risk factors for AD include being a carrier of an apolipoprotein E-epsilon 4 (apoE-ɛ4) allele, particularly for late-onset AD, family history of AD, history of depression, hypothyroidism, and diabetes. This study was a prospective open-label, 6-month pilot medication trial to determine potential salutary effects of memantine on cognition in women at risk of AD. The study design included built-in control for the genetic risk factor for AD (apoE-ɛ4 status). In addition, this study sought to determine whether memantine administration could provide any cognitive benefits to a population of normal postmenopausal women with at least one other putative risk factor for AD.