There is a high and increasing incidence of dementia, depression and other affective disorders, delirium, and other mental health problems, such as psychoses, among older individuals in the United States today (Luijendijk et al., 2008; Rosenberg, Woo, & Roane, 2009). Accurate and timely clinical diagnoses of these illnesses is essential for the development of optimal treatment and management plans (Kapp, 2002b). Nevertheless, because the severity of mental illness, in terms of cognitive and behavioral impairment and therefore the illness' impact on functional ability, varies for different patients at different times along a continuum (Hachinski, 2008; Okonkwo et al., 2007), there is not an automatic, precise correlation between an older person's clinical diagnosis and a simple, dichotomous determination that the individual definitively does or does not possess sufficient present capacity personally to make various sorts of fundamental life decisions. Such matters include medical care, legal transactions like executing a will or entering into a contract (Streisand & Spar, 2007), financial transactions (Hebert & Marson, 2007; Moye & Braun, 2007), living location and arrangements, and research participation (Karlawish et al., 2008). "Neuropsychological tests do not map directly on to legal constructs" (Wood, 2007, p. 202). Put differently, there frequently is a huge difference between a general psychological assessment done for diagnostic and/or therapeutic reasons on the one hand and an evaluation done for purposes of determining a person's capacity autonomously to make specific kinds of decisions on the other (Moye, 2007).
Thus, a large amount of well-funded psychological and psychiatric research has been undertaken over the past few decades aimed at developing instruments useful for the specific purpose of reliably measuring decision-specific decisional capacity among older individuals (e.g., Lai et al., 2008). Decisional capacity assessment in the aged carries important implications both for the official adjudication of legal competence and for patient/client management in the vast majority of cases involving "bumbling through" rather than formal invocation of the guardianship or conservatorship process (Kapp, 2002a); because of those tangible legal and practical consequences, this corpus of research and its resulting output have received tremendous attention in the gerontological and geriatric literature.
A nice summary of the leading work in this arena has been gathered and commented on in Changes in Decision-Making Capacity in Older Adults: Assessment and Intervention (Qualls & Smyer, 2007), a volume in the Wiley Series in Clinical Geropsychology comprised of papers emanating from a conference of clinical and academic geropsychologists held at the University of Colorado at Colorado Springs on this subject. This book explicitly addresses the complicated and nuanced topic of capacity as one at the "intersection of legal doctrine, behavioral science research, and clinical practice" (Smyer, 2007, p. 5) and involving "three interacting elements: the person, the process, and the context" (Smyer, 2007, p. 6).
Changes in Decision-Making Capacity in Older Adults illustrates an interesting phenomenon. Almost all the organized attention that has been devoted to the creation and study of emerging tools and methods for assessing decisional capacity among older individuals and to the legal ramifications of these capacity evaluations begins with the implicit assumption that a mental capacity/ competence assessment of the older person utilizing available appropriate assessment instruments will be done as a primary means of generating the necessary data going into a conclusion about the patient/client's actual and legal ability - and right - to make personal decisions. The assumption appears to be, "First, assume a proper assessment has been done." However, this assumption is not in every case borne out factually. …