Co-occurrence of depression and anxiety in elderly subjects aged 90 years and its relationship with functional status, quality of life and mortality Gerda M. Van der Weele 1 * , Jacobijn Gussekloo 1 , Margot W. M. De Waal 1 , Anton J. M. De Craen 2 and Roos C. Van der Mast 3 1 Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, The Netherlands 2 Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands 3 Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands SUMMARY Objective To examine the prevalence of concurrent depression and anxiety and its relationship with functional status, quality of life and mortality in individuals at age 90. Methods In the Leiden 85-plus Study, a population based cohort study, depression (15-item Geriatric Depression Scale 5 points) and anxiety (Anxiety Screening Questionnaire 1 positive answer) were assessed in all 90-year old subjects with 19 points on the Mini Mental State Examination (MMSE). Functional status included: cognitive function (MMSE) and disability in activities of daily living (Groningen Activity Restriction Scale). Quality of life included: loneliness (Loneliness Scale of De Jong-Gierveld) and life satisfaction (Cantril’s ladder). For all subjects mortality data were available up to a maximum age of 95.3 years. Results Of the subjects aged 90 years with MMSE 19 points (56 men, 145 women), 50 subjects (25%, 95% CI 19–31%) experienced depression and 25 subjects (12%, 95% CI 9–18%) anxiety; of them 34 (17%) experienced depression only, 9 (4%) anxiety only, and 16 (8%) both depression and anxiety. Presence of depression was associated with an overall decreased functional status and quality of life and with increased mortality. Within the depressed group, subjects with anxiety did not differ from subjects without anxiety, except for higher loneliness scores. Conclusion Among individuals aged 90 years, depression and anxiety and their co-occurrence are highly prevalent. Anxiety does not add to poor functional status and increased mortality beyond that associated with depression, and is probably part of the phenomenology of depression in old age. Copyright # 2008 John Wiley & Sons, Ltd. key words — aged 90; nonagenarians; primary health care; depression; anxiety; functional status; quality of life; mortality INTRODUCTION In elderly people co-occurrence of depression and anxiety is highly prevalent (Gorman, 1996; Beekman et al., 2000) and it is well-documented that both disorders are related to reduced functional status and quality of life. Also, in old age depression has been shown to increase mortality (Vinkers et al., 2004). Furthermore, concurrent depression and anxiety is a more severe and more chronic form of psychopatho- logy (Lenze et al., 2000; van Balkom et al., 2000; Schoevers et al., 2003, 2005; Diefenbach and Goethe, 2006). Recently, several studies have investigated the prevalence of concurrent depression and anxiety among community-living elderly people, most focus- ing on formally diagnosed depressive and anxiety disorders among relatively young elderly subjects. The findings of these studies are inconsistent, describing different rates of prevalence of concurrent depression and anxiety. Among non-institutionalized individuals aged 65–86 years living in Amsterdam, the Netherlands, only 1.8% of subjects had both a major INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY Int J Geriatr Psychiatry (2008) Published online in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/gps.2162 *Correspondence to: Dr G. M. Van der Weele, Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, The Netherlands. E-mail: g.m.van_der_weele@lumc.nl Copyright # 2008 John Wiley & Sons, Ltd. Received 28 May 2008 Accepted 7 October 2008