Some Normative and Psychometric Data for the Geriatric Depression Scale and the Cognitive Failures Questionnaire from a Sample of Healthy Older Persons

As part of a study of the effect of lowering homocysteine concentrations on the cognition of the elderly, the Geriatric Depression Scale (GDS) and Cognitive Failures Questionnaire (CFQ) were administered to a sample of persons over the age of 65. Normative data from 272 healthy study volunteers, screened for the presence of major medical, neurological, and psychiatric conditions are presented for both the long and short (GDS-15) versions of the GDS, and the CFQ. Scores on the GDS were correlated with age, but not premorbid IQ as measured by the National Adult Reading Test, highest educational attainment, or gender. Percentile values are presented for comparing obtained raw scores with the normative data for the GDS, GDS-15, and CFQ. In addition, a regression equation is presented for determining age-based predicted scores on the GDS, together with percentiles for evaluating the discrepancies between obtained and predicted scores. CFQ scores were not correlated with any relevant demographic factors, including age, but were associated with scores on the depression scales. Both the GDS and CFQ were found have acceptable internal consistency and retest reliability, and to be comprised of items with good face validity. Depression is a common accompaniment of old age. Estimates of the prevalence of depression in older persons vary widely, depending on the diagnostic criteria and measures used, and the population tested, however, prevalence rates of between 10% and 19.5% for persons over the age of 75 have been reported in the UK (Osborn et al., 2002) and are likely to be similar in New Zealand. Depression is a treatable condition that often goes unrecognised (Rabins, 1996), causing burden in families and increased use of medical services. The identification of depressive syndromes in the elderly is a major health priority, particularly as the population ages. In addition to screening for depression, assessment of the elderly in the clinical setting often involves administration of neuropsychological tests and self-report measures of general cognitive or memory failure. The self-report scales are often used to assess the difficulties clients with neurological damage may be experiencing in everyday life and to provide an insight into their awareness of any clinically significant cognitive changes. Because of the prevalence of cognitive failure and depression in the elderly, the availability of valid and reliable measures of these factors, together with appropriate norms, is of importance in clinical practice. Accordingly, the present research aimed to collect normative data and examine the psychometric credentials of two self-report measures commonly used to assess older persons in New Zealand, the Geriatric Depression Scale (GDS) and the Cognitive Failures Questionnaire (CFQ). The GDS is a self-report inventory, constructed to assess depression and general well-being in the elderly (Yesavage, Brink, Rose, Lum, Huang, Adey, & Leirer, 1983). The GDS has been widely accepted by clinicians because of its ease of use (Dunn & Sacco, 1989; Olin, Schneider, Eaton, Zemansky, & Pollock, 1992), and the absence of items assessing somatic and vegetative symptoms makes it more appropriate for administration to the frail elderly than other symptom-based scales (Hyer & Blount, 1984), such as the Beck Depression Inventory (BDI). To facilitate the use of the GDS as a rapid screen for a clinically significant levels of depression in the elderly, shorter versions of the scale have been published (Almeida & Almeida, 1999), the most widely used being a 15-item version (GDS-15) constructed by Sheikh and Yesavage (1986). The items selected for this scale (Table 3) have content that is primarily focused on symptoms consistent with a clinical diagnosis of depression, whereas the full scale includes a broader range of items and is more sensitive to mild to moderate changes in mood. A correlation between the GDS and GDS-15 of . …