Depression in Late Life (1994)

SUMMARY In view of the growing elderly population in Hong Kong, much emphasis should be paid to the medical service and social welfare for the elderly. Depression is not only a common problem but also causes a great deal of mobidity or even mortality in this age group. In this review, the authors would like to address this issue with reference to its epidemiology, clinical presentation, aetiology, prognosis and treatment. Keywords: review, depression, elderly INTRODUCTION In the recent few decades, there has been a rapid increase in the elderly population in Hong Kong. In 1965, there was 130,900 people older than 65 in a general population of 3.6 million. It composed 3.6% of the total population. However, in 1992, the elderly population raised up to 519,800 in a total population of 5.8 million. The proportion increased to 8.9% (Lee 93). It would be certainly true to expect that the elderly population would rapidly increase in the future. Therefore the need of psychogeriatric service in Hong Kong is a matter of urgency. Depression Is not only a common symptom in the elderly, it can also be a major psychiatric disease in this age group. However it was found to be easily misdiagnosed or undertreated (NIH Consensus Development Panel 1992). If they are not properly treated, it would result in a great deal of morbidity or even mortality. Therefore, clinical awareness of elderly depression is mandatory among the health care professionals. In this review we will discuss recent data on the epidemiology, symptornatology, causes, treatment & the outcome of elderly depression. EPIDEMIOLOGY For major depression which satisfied the DSM-III-R criteria, the prevalence rate in the community was found to be 1% (Blazer 1989). Another study showed 1-2% persons living in the community had major depression while 2% had dysthymia or neurotic depression (Blazer, 1987). On the other hand, the subsyndromal depression had prevalence rate of 8-15% in the community (Blazer 1989). Higher figures were found in people living in institutions. It was found that 15-25% of the nursing home residents had major or minor depression (NIH Consensus Development Panel 1992). There was 13% of new case & 18% of new depressive symptoms in 1 year period in nursing homes. Therefore it is rather common for elderly patient to have depressive symptoms but not the genuine depressive disorder when strict diagnostic criteria is applied. And yet the prevalence rate of major depression in elderly is lower than that in younger adult (Blazer 1987). There may be an increased prevalence among those aged 95 or above, but the current data are too limited for accurate estimates. In Hong Kong, the prevalence of depression In elderly male and female was 29.2% and 41.1% respectively when they were screened by 15-Items Chinese version of Geriatric Depression Scale with cut-off point at 8 (Woo et al 1993). An even higher figure of around 40% was found in our local elderly centres when a Chinese version of Geriatric Depression Scale (30-items) with lower cut-off point (equivalent to 6 on the 15-items version) was used to screen for depression (Yung 91). The high rate in Hong Kong could be explained by the biased samples and the use of different screening instrument or diagnostic criteria. Geriatric Depression Scale was designed Specifically for elderly Population. It has better discriminative power for depression because It excludes the somatic symptoms which are commonly found in the elderly with physical illness. As a research tools, It Is easily administrated even by non-psychiatrists. A rather high false positive rate of 57.1% was noted with 11 as a cut off point in the 30 item version when applied to local people attending government psychiatric clinics in Hong Kong (Chan 94, personal communication). However, it serves as a screening tool that would also include those subsyndromal patients who do not satisfy the diagnostic criteria of depressive disorder in either ICD10 or DSNMIR and further follow up studies are recommended. …