Millions of Americans within the age of 65 and older suffer from diagnosed depressive disorders. It is estimated as of 1995 was at least 2 million of the 35 million older adults are formally diagnosed (Conwell et. al, 1995). These include major depressive disorder, bipolar disorder, or dysthymic disorder. In addition, other symptoms which do not fully meet the requirements of a disorder are also considered common among the elderly. Though the belief persists that depression is synonymous with aging and that depression is in fact inevitable, there has been recent research which dispels this faulty notion. Depression has a causal link to numerous social, physical, and psychological problems. These difficulties often emerge in older adulthood increasing the likelihood of depression, yet depression is not a normal consequence of these problems. Studies have found that age isn't always significantly related to level of depression, and that the population of the oldest old may even have better coping skills to deal with depression, making depressive symptoms more common, but not as severe as in younger populations.
The recognition of depression among older adults is more difficult compared with early life. Often clinicians and patients may mistakenly attribute depressive symptoms on the aging process. This is in part because the level of functioning of older adulthood is perceived lower. The relationship between depressive symptoms and age is ambiguous, but a new study using an elderly community sample suggests that age was not significantly related to level of depression. In particular, this study is a controlled analysis of subthreshold depression, a type of depression not meeting the diagnostic criteria, yet still associated with functioning and impairment. The study hypothesized that subthreshold depression in adults would be higher then the number of adults meeting the Center for Epidemiological Studies-Depression scale of 16 or more. Though this criterion does not usually fulfill the American Psychiatric Associations criteria for major depression, it is a higher classification of depression than subthreshold depression. In a sample of community dwelling elderly, a baseline survey was taken of 4, 162 residents. The prevalence of subthreshold depression was 14.7% and the incidence major depression was at a much lower 3.7% (Hybels et. al, 2000). Overall, depressive symptoms not meeting the CES-D threshold were very prevalent in older adults. 19% of the sample had six or more depressive symptoms in the week prior to the survey. Of the sample that depressive symptoms were present, it was found that they were significantly associated with a poorer rating of self-health, limited physical functioning, medication use, and perceived low social support (2000). The study suggests that the relationship between age and depression is indirect through over variables such as physical functioning.
One limitation to this study is that the sample was drawn from community dwellers who may not be representative of older adults who reside in long term care facilities. In addition, further research needs to study the course of subthreshold depression and the prevalence of relapse. The findings also do not stipulate whether decreased functioning is a result of decreased activity of if decreased functioning leads to depression. Nevertheless, this study exemplifies the relationship between physical and social limitation and depression. The inevitability of the type of depression doesn't solely rest on age.
A longitudinal study of people age 80 and over explored the relationship between age and depressive symptoms. A twin study of 702 Swedish twins over age 80 studied not only the rates of depression in later life, but also whether a qualitative difference existed in the experience of depressive symptoms. Four statements used in the CES-D rating were used as criteria to indicate the lack of well-being for the twins studied. The oldest age group was found to endorse fewer statements of hopefulness and happiness. The measurements were continued by two follow-ups, two years apart. Measures of education, the level of activities of daily living, loneliness, and the diagnosis of dementia were also predictors of depressive symptoms. Prevalence of depressive symptoms over time was found to decrease between the first and second measurements and then remain the same between the second and third measurements (Haynie et, al. 1999). The study emphasized the importance of recognizing depression symptoms in older adults because they represent a different kind of experience. Lack of well-being was found not to alter because of the desirability of events, but because of the expectation from these life events. The oldest old might have different expectations out of life events, changing the measure of depressive symptoms they exhibit. The study is formative in suggesting that those who survive into the very old category may have different coping mechanism and a combination of physical and psychiatric advantages that separate and lessen their depressive symptoms from other populations.
The extent to which the findings from the sample of twins can be generalized, is a potential limitation, in addition to the tendency to answer items in a socially desirable way. Both twins being alive, could bias the sample toward better functioning individual (1999). Given the availability of the data, the potential benefits are believed to outweigh the data.
Another longitudinal study analyzed the correlation between anxiety and depressive symptoms in older adults. This study was also composed of twins, same-sex Swedish twins, with the mean age being 60.9 years. Depression was measured with a 20 item questionnaire using the CES-D scale. Anxiety was assessed by 10 questions from the State-Trait Anxiety Inventory. The results showed that anxiety and depression were more highly correlated in a sample of older adults than in most samples of younger adults (Wetherell et. al, 2000). What is significant about this study is that it differentiated anxiety and depressive symptoms. Anxiety symptoms were more stable than depression. Over two 3-year intervals anxiety symptoms were found to lead to depression. This was not a reciprocal relationship. Depressive symptoms did not lead to anxiety. Anxiety symptoms reflected a personality trait such as neuroticism, whereas depressive symptoms did not. This is consistent with past research that reports similar findings in children and middle aged women, thus supporting the suggestion that depression may not be as specific to older adults as it is to younger populations because the findings are stable throughout the lifespan. In contrast, it was also found that depressive symptoms fluctuated more than the most stable characteristics of anxiety, putting more emphasis on the influence of the context of the situation with depressive symptoms than with the age the depressive symptoms occurred.
Often the case with longitudinal research, one limitation was the older participants were more likely to be lost due to death of inability to complete the survey as time progressed. One benefit to counterbalance this disadvantage was that this study drew from a broad range of older adults, from middle life to late life.
Each study recognized the complexity of depression, especially in older adulthood, and the necessity to due further research examining the causes and treatments. In addition, current research is quite sensitive to be correct and distinguish depression between younger populations and older adults. Decreased physical functioning, illness, lack of support, and loneliness are just a few of the characteristics that contribute heavily to depression within older adults. Research has shown that depression is in fact not inevitable. In some cases, the oldest old might even inherit advantages to coping with life struggles. Concerning depression, age is a variable closely linked to a realm of social, psychological, and physical factors. It is imperative that further research be done to examine other factors besides age so that the many who suffer from this disorder can effectively seek relief and be eased of this pain.
Haynie, Dee A., Berg, Stig., Johansson, Boo., Gatz, Margaret., Zarit, Steven H. (1999). Symptoms of Depression in the Oldest Old: A longitudinal Study. Journal of Gerontology: Psychological Sciences 2001, Vol56B, No.2, P111-P118.
Hybels, PhD., Celia F., Blazer, MD, PhD., Dan G., Pieper, DrPH., Carl F. (2000). Toward a Threshold for Subthreshold Depression: An Analysis of Correlates of Depression: An Analysis of Correlates of Depression by Severity of Symptoms Using Data From an Elderly Community Sample. The Gerontologist 2001, Vol 41, No. 3, 357-365.
Wetherell, Julie L., Gatz, Margaret., Pederson, Nancy L. (2000). A Longitudinal Analysis of Anxiety and Depressive Symptoms. Psychology and Aging 2001, Vol. 16, No. 2, 187-195.
Diagnosis and Treatment of Depression in Late Life (http://text.nlm.nih.gov/nih/cdc/www/86txt.html)
National Depressive and Manic Depressive Association (http://www.ndmda.org/)
National Institute of Mental Health (http://www.nimh.nih.gov/)
Contributed by Jennifer A. Hill, October 4, 2001.