This study explored the disparities of depression among older adults with chronic conditions. The results from a longitudinal analysis provided a developmental and comprehensive understanding of factors associated with depression.
The results showed that the most reported chronic conditions were chronic physical impairments (CPIs), far more than chronic diseases (CDs). Specifically, the top five reported CPIs were vision impairment (n = 2407, 68.0%), followed by chronic pain (n = 2126, 60.0%), fatigue (n = 1669, 47.1%), lower body strength limit (n = 1271, 35.9%), and upper body strength limit and the issue of balance (n = 1126, 31.8%). All of these CPIs are associated with body movements and mobility, impacting the capacity to perform daily tasks independently (Reid et al., 2015). Besides, the top three reported CDs were cancer (n = 518, 14.6%), heart disease and heart attack (n = 505, 14.3%), and diabetes (n = 468, 13.2%). All of these CDs require older adults to utilize healthcare services and prescription drugs regularly and periodically. The results of chronic conditions in this study are consistent with the latest report of Centers for Disease Control and Prevention (CDC) that 2 in 5 adults age 65 and older are affected by dysfunction and other mobility-related limitations, and cancer, heart disease and heart attack, and diabetes are among most reported chronic diseases (Villarroel et al., 2019). The results also represented that among 3541 participants, 375 (10.6%) participants reported having depression. This result is consistent with the CDC’s report that the depression rate among older adults living in the community ranges from less than 1% to about 5% but rises to 13.5% in those who require home healthcare and 11.5% in older hospitalized patients (CDC, 2017). Risk and protective factors of depression among U.S. older adults with chronic conditions are discussed below.
Findings from factors in the personal system showed that age is significantly associated with depression over time. Specifically, compared to participants who were 65 to 69 years old, those aged 80 and older were less likely to have depression, and the older the participants, the lesser likely to have depression. As the population ages, especially for those who were 80 + years old or even 90 + years old, survivorship plays a pivotal role in the low level of depression. For example, the oldest-old view their late-life and health condition more positively than younger older adults since recognizing that they have lived well beyond their expected lifespan or they are survivors of their chronic conditions (DeSantis et al., 2019). Besides, people who live into their 80s and 90s will more likely have fewer health problems than those who died at earlier ages, which may contribute to lower levels of depression (Cho, 2011).
In addition, according to the Transactional Theory of Stress and Coping (TTSC) model, suffering chronic conditions can be a stressful life event to older adults, triggering appraisal and then prompting older adults to cope with this stressor by invoking their coping resources. When the applied coping strategies fail to address the influence resulting from chronic conditions, this failure initiates further coping strategies, and its resultant distress may trigger meaning-focused coping (MFC), particularly when older adults perceive that stressors like suffering chronic conditions are overwhelmingly uncontrollable. Older adults may ascribe positive meaning to suffering chronic conditions or find and remind themselves of the benefits of this stressor. For example, although they are suffering chronic conditions and have to endure its negative influences over time, it provides more opportunities for them to spend time with their caregivers who are usually their family members. Older adults can benefit from this advantage to reorder their life priorities from focusing on chronic conditions to the relationships, especially when they are at an older age when medical treatment is futile to offer additional benefits (Moorman, 2011). Meanwhile, this advantage can also alleviate their depression from suffering chronic conditions to further sustain extant coping efforts over time (Folkman, 2008).
The results further presented that compared to White participants, Black, Indian/Asian/Native Hawaiian/Pacific Islander, and Hispanic were more likely to have depression. This result is consistent with a multitude of studies showing that older adults of color are more likely to experience mental disorders, like depression, due to the disparities in socioeconomic status (Bui et al., 2020). Moreover, older adults with higher socioeconomic status, like higher annual income, can greatly reduce the occurrence or severity of mental disorders since they can access more healthcare and life resources (Xue et al., 2021).
Findings from factors in the environmental system showed that compared to participants who reported excellent self-rated health, those who reported good, fair, and poor self-rated health were more likely to have depression. Besides, the worse the self-rated health, the more likely to be depressed over time. According to the TTSC model, coping with stressful life events, like suffering chronic conditions, is an appraisal-coping-reappraisal process that appraises whether the stressor produces harm, threat, or challenge. Or this process reappraises whether the coping efforts have been successful or determines if the nature of the situation has changed from stressful to irrelevant, benign, or positive (Lazarus & Folkman, 1984). Regardless of whether the participants first encountered the stressor (i.e., suffering chronic conditions) or already applied coping strategies to cope with this stressor when the survey was administered, fair or poor self-rated health as unfavorable appraisal may exacerbate individual’s mental or physical distress, leading to depression. This result is consistent with a slew of studies suggesting that older adults who poorly rate their health are more likely to be depressed (Campos et al., 2015).
Findings further presented that older adults who had more chronic conditions were more likely to have depression over time, but those who had better cognitive capacity were less likely to have depression over time. According to the TTSC model, older adults may appraise the severity of their chronic conditions and then invoke coping resources to address this stressor. Negative emotions and feelings can result from unfavorable appraisal or unsuccessful coping over time when their chronic conditions do not become better or even grow worse and more. Just as the results of psychological factors represented, participants who had more negative feelings, worse self-realization, and worse self-efficacy and resilience were more likely to have depression over time. These results are consistent with a wealth of studies asserting that the more comorbidities older adults have, the more likely to stress themselves and their caregivers, bringing physical or mental distress (e.g., negative emotions or bad self-realization and self-efficacy) and eventually result in mental disorders like depression (Mindlis et al., 2021). Besides, having better cognitive capacity as one of the powerful coping resources can facilitate older adults better manage their chronic conditions when synergistically applying other coping resources during their coping processes over time. This result is consistent with multiple studies presenting that older adults with better cognitive capacity are more likely to be able to address mental distress (e.g., negative emotions or bad self-realization and self-efficacy) resulted from suffering chronic conditions, and to make proper plans for their healthcare services and life so that increase the possibility to bring about positive outcomes for their physical and mental health (Dragioti et al., 2021).
The results of social factors showed that participants who actively utilized coping resource “activity participation” by attending more physical activities and social activities were less likely to have depression over time. According to the TTSC model, older adults not only take actions to cope with the impacts of extant stressor that is suffering chronic conditions, but also apply future-oriented coping to avoid negative influence or outcomes from possible stressors. Attending physical activities regularly can benefit older adults with chronic conditions with health improvements and protecting them from getting additional chronic conditions (Taylor, 2014). Besides, attending social activities offers peer support, encouragement, or emotional relief to older adults from friends and other people outside the family. Using technology devices, like cellphones, computers, and tablets, further facilitate older adults to build connections with people and access supportive information to mitigate the negative emotions or mental disorders from suffering chronic conditions (Stacy et al., 2020).
In addition, the findings of this longitudinal study revealed a pattern of how depression changed over time in that depression was less likely to occur over time. However, this pattern existed in two consecutive visits only, suggesting that although depression tends to decrease over time, it happens in a relatively short time range that is one year. Besides, the odds ratio of visit 5 (eb= .797, P = .011) is higher than visit 4 (eb= .683, P < .001), meaning the occurrence of depression at visit 5 is higher than visit 4, or the likelihood of the decrease of depression is lower at visit 5 compared to visit 4. It further suggests that although the occurrence of depression declines over time, the extent of decline slows down gradually. This finding further calls for joint efforts involving policymakers, healthcare practitioners, researchers, and social workers to develop new and creative mental health programs and interventions to help minimize the impacts of depression by extending the decline of depression over time.
LIMITATIONS AND FUTURE DIRECTIONS
The findings of this study presented a relatively comprehensive understanding of the risk and protective factors of depression among U.S. older adults who were suffering chronic conditions. However, some limitations in this study should be noted to advance the knowledge and understanding in future studies.
The primary limitations of this study are related to the research methodology. For the measurement of dependent variables (i.e., depression), the NHATS survey applied a brief screening instruments: The Patient Health Questionnaire-2 (PHQ-2) for depression (Kasper & Freedman, 2020). Since brief measurements may sacrifice the precision or reliability of the results (Kohout et al., 1993), future studies can use detailed measurements to assess depression. For example, the Patient Health Questionnaire-9 (PHQ-9; Kroenke et al., 2001) may be used in future studies. Despite this limitation, a multitude of studies have used PHQ-2 to explore relationships between depression and various predictors (Hamedani et al., 2020; Jones et al., 2016; Levine et al., 2018).
Besides, the NHATS survey measured age by categorizing continuous data into six categories (0 = 65 to 69, 1 = 70 to 74, 2 = 75 to 79, 3 = 80 to 84, 4 = 85 to 89, 5 = 90+). Since continuous variables applying a simple linear or polynomial function can adequately describe the relationship between the response and the predictor (in this study, the relationship between depression and the age; Royston et al., 2006), future studies can apply continuous data for measuring age. Moreover, the NHATS survey does not collect certain data, like geographic region, so that this study was limited to use this predictor to comprehensively explore more about whether the urban or rural area has a significant association with the disparities of depression. Future studies can involve this factor to present a more holistic picture of depression. In addition, the cohorts in the analysis were unweighted, prompting further analyses to apply analytic weights to adjust for differential nonresponse and produce national prevalence estimates to show the relationship between depression and selected predictors.
Finally, this study is limited by its inability to generate conclusions related to the comparison among chronic conditions to show which specific chronic conditions were significantly associated with depression among U.S. older adults over time. Future studies can focus on the comparison to contribute to the knowledge of depression across different chronic conditions by using data collected from clinical trials. Future studies can also explore this relationship more in-depth using qualitative methods, such as case studies.