Introduction

Countries across the world are experiencing an ageing population phenomenon. It is projected that the population of older adults in the world will rise by 21% in the next 50 years and by the year 2050 there will be an expected quadruple increase in the elderly population to almost two billion in the developing countries [1]. The population of Malaysia is 25 million and is made up of several ethnic groups, comprising mostly of Malays and other indigenous groups followed by the Chinese, Indian and non Malaysian citizens who mainly comprise of immigrant labourers [2]. In the past two decades there has been a change in the demographic profile of Malaysia’s population. It is estimated that by the year 2020, almost 10% of Malaysia’s population will be 60 years and above. This is due to improved health, longer life expectancy, low mortality as well as declining fertility [3]

Although mental health is important to the elderly, only a fraction of those who need mental health care receive it [4]. By one estimate only about 10% of older adults who are in need of psychiatric treatment ever receive this service [5].

Depression in a broad sense can describe a syndrome that includes a constellation of physiological, affective and cognitive manifestations. Depression causes functional impairment and imposes an immense burden on individuals, communities and heath services. Depression may range in severity from mild symptoms to more severe forms that include delusional thinking, excessive somatic concern and suicidal ideation over long periods of time [5]. Depression is insidious that neither the victim nor the caregiver may recognize its symptoms. Depressed mood, the typical signature of depression, may be less prominent in older adults than the depressive symptoms such as loss of appetite, sleeplessness, anergia and loss of interest and enjoyment for the normal pursuits of life [5]. Depression in the elderly is commonly misdiagnosed and under treated. The untreated depressed elderly have significant clinical and social implications as these disorders decrease the individual’s quality of life and increase dependence on others.

Prevalence of depression in the Asia- Pacific region is comparable to that of the Western world [6]. The prevalence of depression in central Malaysia has been shown to range from almost 8% in rural communities [7] to 6% in urban communities [8]. The population of the elderly is the highest in northwest Malaysia. Here the prevalence of depression has been reported as high as 48.8% in the community [9] and 67% in an elderly care institution [10].

Geriatrics and psycho geriatrics are emerging specialties in Malaysia, and so to date there has been relatively little research in these areas. However there is evidence from other countries that depression is an important problem in the elderly causing a large amount of morbidity and mortality in this group

The objective of this study was to determine the prevalence of depression among the elderly Malays living in a rural region of north Malaysia.

Methodology

Setting: 24 villages were selected from a north western state in Malaysia called Kedah which has one of the highest rates of elderly population in the country. All villagers were Malay Muslims and most were working as fishermen and farmers due to the proximity of the villages to the sea and the foot hill of a mountain.

Study Design: a cross sectional study was chosen as the study design. The study was conducted from 2008 to 2009.

Sampling: respondents were taken from among the elderly residents living in these villages. Those who consented and who were able to communicate effectively were eligible to participate. Only the participants who were not cognitively impaired were selected to undergo screening for depression.

Tools: the data was collected by trained research assistants using a questionnaire especially designed for this study. The interviews were conducted in the participants homes. Ringgit Malaysia (RM) 600 was used for categorizing family income because at the time of the study the cut off for poverty line was about RM 600. Besides the baseline demographic information, Geriatric Depression Scale (GDS) was used to screen for depression. The GDS is a questionnaire which is widely used as a screening tool for depression in the elderly [11]. The participants were asked to respond to 30 questions by answering ‘yes’ or ‘no’ in reference to how they felt on the day the questionnaire was administered. Scores of 0-9 indicated normal, 10-19 mild depression and 20-30 indicated severe depression. The GDS was found to have 92% sensitivity and 89% specificity when evaluated against formal interview diagnostic criteria. The validity and reliability of the tool have been supported through both clinical practice and research. The validated Malay [12] version was used.

Due to the complexity of the questionnaire, only participants who were not cognitively impaired were screened using the GDS. Elderly Cognitive Assessment Questionnaire (ECAQ) was used to screen the participants for cognitive impairment. ECAQ is a ten item screening test assessing long term memory, orientation and recall validated in Singapore and is a useful tool for routine screening. It is used in the developing world for patients who may be illiterate or have a relatively low level of education [13]. A score of 7 or more is indicative of normal memory and score of 4 and below indicate probable dementia. Respondents whose ECAQ score was less than 5 were not administered the GDS questionnaire.

In addition, the Barhtel index [14] which is a well established and commonly used nursing tool [5] was used to assess the functional independence in the activities of daily living (ADL). The participants were categorized as independent and dependent according to this index.

Body mass index (BMI) was calculated by dividing weight in Kg with height in metres squared. The index was categorised as <18.5 underweight, 18.5 – 24.9 as normal, 25-29.9 overweight and ≥ 30 obese.

Analysis: analysis was done using SPSS version 13. Chi squared test was used to compare the variables. Binary logistic regression was conducted and odds ratio was used to estimate the risk for depression.

Ethics: the research had received the approval of the institution’s research and ethics committee. All respondents were asked to give an informed consent before starting the interview. The anonymity of the respondents is assured.

Results

There were 428 villagers who were 60 years and above. A total of 418 villagers responded but after screening for cognitive impairment using ECAQ, 46 were excluded. There were more female respondents compared to male, most were within the ages of 60 to 70, married and living with family members. There were almost equal numbers of employed and unemployed respondents. Majority had a family income of less than RM 600 (USD 187) a month. Most were independent and had normal BMI.

The prevalence of depression among older adults was 30.1% (112). As shown in table 1, about 21% (79) had mild depression and almost nine percent (33) had severe depression. Among the sexes more female had severe depression. There was an increasing prevalence of depression as age increased. Presence of depression was higher among those unmarried, living alone, unemployed and earning less than RM 600. There were more individuals with severe depression among those dependent on the activities of daily living and among the obese.

Figure 1

Table 1 descriptive analysis of depression

Risk analysis

As shown in table 2, there was about a two fold risk of being depressed when the respondent was unmarried (OR 2.06. 95% CI 1.20;3.54), unemployed (OR 1.81. 95% CI 1.13;2.91), having an income less than RM 600 (OR 2.16. 95% CI 1.21;3.88) and living alone (OR 2.32. 95% CI 1.25;4.31). Differences in gender, age, disability, BMI and hypertension were not found to be statistically significant.

Figure 2

Table 2 Risk analysis for depression

Multivariate analysis

A binary logistics regression was attempted using marital status, employment, income and living arrangement as predictor variables. Occupation (OR 1.82. 95% CI 1.13;2.95) and Income (OR 1.79. 95% CI 1.03;3.14) were found to be significant predictor variables. The model had -2 likehood ratio of 435.985, Cox and Snell R squared 0.058 and Nagelkerke R square 0.082.

Figure 3

Table 3: Logistic Regression

Discussion

Depression is often reversible with prompt and appropriate treatment. If left untreated depression may result in the onset of physical, cognitive and social impairment as well as delayed recovery from medical illness and surgery, increased health care utilization and suicide.

World Health Organization (WHO) estimates that depression will be a major burden of illness in most developing countries [15]. Geriatric depression affects at least one in six patients treated in general medical practice and even higher percentage in hospitals and nursing homes [16]. It is estimated that 10 to 15% of older adults in the United States of America are inflicted with depression [17 & 18] and this number increases among the institutionalized elderly [16]. Similar prevalence is found in United Kingdom [19]. It is estimated that the prevalence of depression is about the same in the Asia Pacific region as in the western world [6]. Studies in Indonesia, Vietnam and Japan have shown the prevalence of depression to range from 17% to about 33% [20]. However the prevalence of depression among the elderly was found to be relatively low in rural China [21]. Although the prevalence depression was higher in this study as compared to the prevalence of depression in central Malaysia [7&8], it is still lower than the prevalence of depression in north Malaysia [9&10].

Marriage has been shown to be a protective factor against depression in the elderly [21]. The findings of this study is similar to other studies conducted in health clinics in Malaysia [22&23] and to studies conducted in South America [24&25] which showed higher risks of depression among unmarried older adults. It is assumed that married people are exposed to lesser stressful experiences throughout their married life and thus decrease the risk of being depressed. Another reason for this could be that unmarried older adults may feel loneliness because of the lack of companionship. Being lonely is a risk factor for depression. Older adults who live alone or in residential homes are susceptible to loneliness [26]. Having family members who care for their elderly have been found to be a protective factor against depression [25]. Findings of this study along with other studies conducted in Malaysia have shown low social support as a risk factor for depression [27&28].

Studies have reported a relationship between unemployment and ill health especially mental health [29,30&31]. Studies have also reported that there is a double risk of depression among the unemployed [32]. Employment enhances one’s self confidence, self esteem and empowers people to have control over their future and makes an individual feel like a valuable member of the community [33&34]. Occupation and economic status of an individual are closely related. People with low income have been shown to have depressive symptoms [24&35]. Low economic status has also been shown to be an impediment to receiving healthcare [36]. Malaysia’s per capita income has risen from USD $ 3 843 in 2002 to USD$ 7 734 in 2008 and it is projected to increase to USD$ 15 340 in 2020. Despite the remarkable growth in the economy and the progress in poverty eradication in Malaysia [37], the economic status of the elderly is still lagging behind. This could be because of the difficulty in finding jobs with fair wages suitable to them in rural Malaysia. Rural areas are often economically disadvantaged due to lower levels of development and limited work opportunities. In this study those who were unemployed and those with low income were at a higher risk of having depression. Similarly other studies conducted in clinical settings in Malaysia have shown that elderly patients who were satisfied with their income were less likely to be depressed [22&23].

Conclusion

The prevalence of older adults with depression is high in Malaysia. The risk factors which were found to be significantly associated with depression are modifiable. Due to migration of young people who are looking for better economic opportunities in cities there is a growing population of older adults in villages. Asset accumulation level of the elderly are very low and very few are on pension causing many older adults to work in old age. Government and the non government agencies should create employment opportunities for this group of people.

Limitations

The GDS used to detect depression in this study is a screening tool; it is not a diagnostic interview which is conducted by mental health professionals. Due to this the prevalence of depression in these villages could be higher than that determined. However, the GDS is a widely used screening tool routinely used in research on depression in the elderly.