By Siegfried Weyerer
Depression in old age occurs frequently, places a severe burden on patients and relatives, and increases the utilization of medical services and health care costs. Although the association between age and depression has received considerable attention, very little is known about the incidence of depression among those 75 years of age and older. Studies that treat the group 65+ as one entity are often heavily weighted towards the age group 65-75. Therefore, the prediction of depression in the very old is uncertain, since many community-based studies lack adequate samples over the age of 75.
With the demographic change in the forthcoming decades, more emphasis should be put on epidemiological studies of the older old, since in many countries the increase in this age group will be particularly high. To study the older old is also important, since some crucial risk factors such as bereavement, social isolation, somatic diseases, and functional impairment become more common with increasing age. These factors may exert different effects in the younger old compared to the older old. Knowledge of risk factors is a prerequisite to designing tailored interventions, either to tackle the factors themselves or to define high-risk groups, since depression is treatable in most cases.
In our recent study, over 3,000 patients recruited by GPs in Germany were assessed by means of structured clinical interviews conducted by trained physicians and psychologists during visits to the participants’ homes. Inclusion criteria for GP patients were an age of 75 years and over, the absence of dementia in the GP’s view, and at least one contact with the GP within the last 12 months. The two follow-up examinations were done, on average, one and a half and then three years after the initial interview.
Depressive symptoms were ascertained using the 15-item version of the Geriatric Depression Scale (GDS). We found that the risk for incident depression was significantly higher for subjects
- 85 years and older
- with mobility impairment and vision impairment
- with mild cognitive impairment and subjective memory impairment
- who were current smokers.
It revealed that the incidence of late-life depression in Germany and other industrialized countries is substantial, and neither educational level, marital status, living situation nor presence of chronic diseases contributed to the incidence of depression. Impairments of mobility and vision are much more likely to cause incidents of depression than individual somatic illnesses such as diabetes mellitus and coronary heart disease. As such, it is vital that more attention is paid to the oldest old, functional impairment, cognitive impairment, and smoking, when designing depression prevention programs.
GP practices offers ample opportunity to treat mental health problems such as depression occurring in relation to physical disability. If functional impairment causes greater likelihood of depression, GPs should focus on encouraging older patients to maintain physical health, whether by changing in personal health habits, advocating exercise, correcting or compensating functional deficits by means of medical and surgical treatments, or encouraging use of walking aids. Additionally, cognitive and memory training could prevent the onset of depressive symptoms, as could smoking cessation. If these steps are taken, the burden of old age depression could be significantly reduced.
Siegfried Weyerer is professor of epidemiology at the Central Institute of Mental Health in Mannheim, Germany. He has conducted several national and international studies on the epidemiology of dementia, depression and substance use disorders at different care levels. He is also an expert in health/nursing services research. He is one of the authors of the paper ‘Incidence and predictors of depression in non-demented primary care attenders aged 75 years and older: results from a 3-year follow-up study’, which appears in the journal Age and Ageing. You can read the paper in full here.
Age and Ageing is an international journal publishing refereed original articles and commissioned reviews on geriatric medicine and gerontology. Its range includes research on ageing and clinical, epidemiological, and psychological aspects of later life.