A discussion of the research reporting findings regarding the benefits of cognitive training for patients suffering from cognitive impairment would be incomplete without noting the relevance of the relationship between cognitive decline and Alzheimer’s disease. The relationship between Cognitive Decline and the development of Alzheimer’s disease as well as need for early intervention is underscored by the NIH research review and discussed further: “Concordance for factors affecting cognitive decline and Alzheimer’s disease has a number of potential implications.
A consistent body of evidence increases our confidence in the observed association. It is also consistent with the proposed analytic framework that the symptoms of AD begin with insidious cognitive decline that progress to more marked cognitive and functional impairment. Finding consistent evidence for cognitive decline and AD would reinforce the potential effectiveness of early interventions that could diminish both the risk of cognitive decline and AD.” (20. page 284, Table 73) In sum, the concordant data for study of Alzheimer’s Disease shows a decreased risk with cognitive engagement, consistent with findings regarding Cognitive Decline and cognitive training, reported above.
Not only does the NIH Review remind the reader of the risk for untreated cognitive decline/Mild Cognitive Impairment to progress into Alzheimer’s disease and eventually, dementia (20. Table 73, p. 293), but this is well known through multiple additional studies. On average, “the total number of patients who had progressed to a dementia [without intervention] in studies lasting less than 5 years was 27.4%; the total number of patients who had progressed to dementia by the end of studies lasting up to 10 years was 31.4%; and rate of conversion was ‘significantly higher’ in the 70-85 year old age group (6.)
The relationship between MCI and Alzheimer’s disease is thus, well-documented, but since the last LCD revision, we have also learned more regarding the importance of early diagnosis in order to intervene and slow progression of cognitive impairment. The recent reports by the National Institute on Aging under NIH, in conjunction with the Alzheimer’s Association urge that the definition of Alzheimer’s must be expanded to include early Alzheimer’s, and also provides new guidelines for scientific study of Alzheimer’s disease (7.,8.,9.,10.) These new guidelines underscore the importance of early diagnosis, conceptual thinking and study of cognitive impairment/Alzheimer’s disease along a continuum, and the need for early intervention: “The pathophysiological process of Alzheimer’s disease (AD) is thought to begin many years before the diagnosis of AD dementia. This long ‘pre-clinical’ phase of AD would provide a critical opportunity for therapeutic intervention” (8., p.1.) [bold added]
The clinical research presented, which has been conducted over the past ten years, provides evidence that cognitive decline can be stabilized, delayed, and even improved by the professionally administered memory/cognitive training.