What is Processing Speed

This chapter describes how one of the challenging issues of clinical diagnosis is distinguishing between the cognitive deficits manifested in normal aging, depression, mild cognitive impairment (MCI) and dementia. The diagnostic challenge is that there is a great deal of overlap in the symptom constellations of these conditions. It is thus important to establish conceptual and clinical criteria with sufficient predictive validity to accurately identify differences and similarities in cognitive states to justify initiation of appropriate treatments.