Mental disorders are one of the critical issues of the aging in the world and Iran, which require essential planning and intervention. Considering the high rate of growth of the elderly population in Iran, the importance of this issue is greater.
In the current study, the prevalence of depression, anxiety, and stress was 45.5, 35.5, and 40.2%, respectively, indicating the high prevalence of these disorders.
In studies conducted in Iran, in line with our findings, a study examined seven databases and reported the prevalence of depression in the Iranian elderly, about 43%, from 2001 to 2015 (25). In a meta-analysis by Esfahani et al., conducted in 2019 among the elderly in Iran, the prevalence of depression was 15% based on the random model, and the highest prevalence was in Khorramabad city with 82.1% and the lowest in Khoy city with 0.003%. The difference was because of different cultures, environmental factors, hereditary factors, and study methods (8). In a study that investigated the prevalence of depression, anxiety, and stress in Yazd adults, these disorders were 29%, 32.2%, and 34.8%, respectively (20).
The prevalence of depression, anxiety, and stress in the elderly of Nepal was 15.4%, 18.1%, and 12.1%, respectively, significantly different from our results (26). The prevalence of these disorders in Ghanaian adults was 25.2%, 53.3%, and 9.7%, respectively. The difference in the results can be attributed to cultural-social factors, economic characteristics, study methods, and different tools (27).
The high prevalence of these disorders in our study indicates the unfavorable status of mental health in the elderly. It can be due to the low access of different age groups to mental health services or their lack of information about these centers, which causes lack of diagnosis of initial symptoms and lack of detection or late detection of infected people. Due to the fundamental changes in Iranian's lifestyle, the transformation of extended families into nuclear families, and the migration of the young generation to the cities, the support structures for the elderly have been weakened, and these people are at a greater risk of suffering from mental disorders.
In the study of the factors affecting depression, anxiety, and stress in the elderly, age, comorbidity, life status, and income status were significant predictors of the risk of these disorders. Increasing age, even weakly, was associated with increasing DASS scores. With increasing age, it can be expected that most elderly will face problems such as loneliness, financial needs, and comorbidities. As a result, they will be exposed to a greater risk of suffering from mental disorders. Nevertheless, the results of different studies are not the same (28, 29).
The results showed that comorbidity significantly increases the risk of DASS. This finding is consistent with other studies that reported comorbidity as the main predictor of mental disorders. Studies show that 81% of people over 65 and 50% of people aged 45–65 in the United States suffer from comorbidity, and it is 47.5% of Chinese elderly people (30). Elderly people with comorbidity need more support and medical services, expose to more healthcare costs, and are often at a higher risk of being hospitalized (31).
In this study, life status were among the factors affecting depression, anxiety, and stress. The results of the univariate analysis showed that the elderly who lived with their mates and children had higher mental health, and depression, anxiety, and stress were less in them. However, this finding was not significant in multivariate regression. The family plays a central role in supporting its members, and living with a spouse and children is one of the most critical factors in the perception of social support, which can increase life expectancy and plays an influential role in the mental health of the elderly (32). In this study, living with children and others was associated with increased depression, anxiety, and stress.
In terms of living with children, there are cases such as the elderly being deprived of spending time as they wish, the responsibility of taking care of the house, doing housework, taking care of the grandchildren (1), the child's negligence, not having enough financial and emotional support, lack of attention to the elderly's needs and even domestic violence. Although the proportion of elderly people living with married children has decreased significantly, elderly people are living with unmarried children who may not have enough financial resources to support their elderly parents (33). As a vital support source, the family helps the elderly maintain their social interactions and protects them from problems such as loneliness, social isolation, and depression. Therefore, the elderly who do not live with family members are deprived of this support and are exposed to many health problems (34).
We observed no significant difference in the DASS score between working and retired people. It could be because retired people have income (although low) that they are not financially dependent on others or have low dependence. The results showed that unemployment and housekeeping are the factors that increase mental disorders in the elderly. Due to the lack of income, the unemployed elderly need the financial support of other family members or supporting organizations. These people face severe challenges because the elderly is associated with chronic and expensive diseases which can cause or aggravate mental disorders. In the study of Moghadam et al., conducted to investigate the relationship between social support and depression in the elderly, the results indicated a higher rate of depression in the elderly with low income (35).
In this study, gender had no significant effect on DASS. Gender is a socio-demographic factor that is often associated with depression and anxiety. The female gender is significantly associated with the increase in these disorders (36–38). The factors involved in this difference in old age are not well known (39), and the results of different studies are not the same. For example, Hosseini et al. studied the relationship between depression, anxiety, and stress with perceived social support in the elderly in Iran, the levels of depression and stress in men were higher than in women (16). In addition, in several studies, no relationship between gender and depression in elderly people was observed (40).
The study's results indicated a mutual effect between comorbidity and income status in depression, anxiety, and stress. This finding indicates that comorbidity and a lower income have a higher DASS score. As mentioned, aging is associated with the possibility of chronic and expensive diseases. The elderly with comorbidities and who do not have a sufficient income, face more problems than others. This issue can have a double effect on increasing their DASS score.
The most important strength of this study was the investigation of the interaction between the variables in this study, which examined their mutual effect on the level of depression, anxiety, and stress and showed the role of comorbidity and income status on the level of depression, anxiety, and stress of the elderly. Nevertheless, one limitation of this study can be the self-reporting of the elderly, who may not be careful enough to provide the answers. Another point is the nature of cross-sectional studies, which cannot examine the cause-and-effect relationship and the temporal precedence.