Giovannetti and co-authors (Giovannetti et al., 2006) highlight the importance of measuring activities of daily living (ADL) and Instrumental activities of daily living (IADL) for the diagnosis of dementia. The method used, Naturalistic Action Test (NAT), is performance based. Study rationale was that “the relevance of diagnosis to everyday functioning has gone largely unexplored.” However, this statement seems to be invalid: cognitive impairment interfering with daily/social functioning is one of the DSM-IV dementia criteria. Secondly, many different ADL/IADL scales exist and are used in dementia research, including those that are performance based (Burns et al., 2004). Authors should have reviewed these scales more thoroughly and present a rationale for introducing a new one. NAT items model household chores and preparing a simple meal only. These activities are quite different from and perhaps easier to perform than using the telephone, handling finances, and similar instrumental activities. Simple activities or ADL may not be useful in differentiating dementia from normality, especially in the early stages of dementia.

Also, the authors do not present data on convergent/divergent validity: is the NAT related to similar ADL/IADL rating scales? This question is much more important than the presented data on NAT-cognitive measures correlations. So, some of the conclusions regarding the relationship between dementia diagnosis and everyday functioning are tautological or at best redundant. Constructing yet another rating scale requires a better study rationale.