Commentary on “The NIH Cognitive and Emotional Health Project. Report of the Critical Evaluation Study Committee”

Cognitive and emotional health, especially of older individuals, has become increasingly important because of the increasing life expectancy and the growing population of older individuals. The report is a comprehensive review of primarily studies of determinants of cognitive and emotional or mental health changes through older ages. The report documents many studies and a large number of potential risk factors. The report has a major flaw in that it fails to attempt to synthesize the information into a coherent picture that would be suitable for hypothesis testing. Human population, especially epidemiologic, studies are a relatively weak tool for measuring normality or average distribution of change because of substantial within-individual variability and selectiv elos st ofollow-u p[1].