Dementia affects approximately 55.2 million people and their families worldwide in 2019, and this is expected to rise to 139 million by 2050 (1). Dementia care may be a long journey characterized by significant neuropsychiatric symptoms, caregiver distress, and unmet needs (2). Behavioral and psychological symptoms of dementia (BPSD) are common non-cognitive impairments occurring at all stages of dementia (3). Around 80%–90% of people with dementia have at least one of these symptoms (4, 5). One of the greatest challenges in caring for people with dementia is managing these symptoms. Difficulty in doing so often leads to higher caregiver burden (6), impaired quality of life (7, 8), increased healthcare utilization (9, 10), and risk of institutionalization (11). The problem is likely to be even greater within the community (12).

Family caregivers are mainly responsible for managing BPSD of people with dementia living at home (13–15), but typically possess only limited knowledge about symptoms and how to handle them (16). The number of people with dementia in China is estimated to exceed 9 million and is expected to reach 40 million by 2050 (17). Around 90% of them live at home and are looked after by their families (18). Dementia care services and related support services are also still developing in China (2). The lack of dementia-related training and community-based support services designed for people with dementia and their families can lead to exhaustion among family caregivers (18). Family caregivers in low- and middle-income countries often experience a higher level of distress due to the lack of resources and support mechanisms in the public healthcare system to help them properly managing BPSD (15, 19).

By comparison with their counterparts in long-term care facilities, we may get a better appreciation of clinically significant and moderate-to-severe distressing BPSD and their risk predictors in community-dwelling older adults with dementia cared by family caregivers. This is necessary to generate research evidence to inform the design of tailored management strategies and support family caregivers to enable people with dementia to stay at home longer, especially in low- and middle-income countries. Previous studies have investigated differences in caregiver distress caused by BPSD between community-dwelling older adults and residents of long-term care facilities (15, 20–22). Cheng and colleagues found that BPSD caused more distress to family caregivers than formal caregivers (20). On the contrary, Loi and colleagues suggest that formal caregivers may be exposed to more severe and frequent BPSD than informal caregivers (22). The discrepancies between the studies suggest that BPSD-induced distress may influence by a myriad of factors (such as country/culture, long-term care systems, outcome measures used, and sample characteristics). Especially, the use of samples with different severity of dementia, as well as a potential influence of medication used by participants, may lead to significant differences in the assessed severity of symptoms and the caregiver distress caused. We hypothesized that after controlling for dementia severity, as well as medication use, we might clarify the difference in BPSD and caregiver distress caused between community-dwelling older adults with dementia and nursing home residents with dementia.

This study therefore aimed to explore differences in BPSD and caregiver distress in responding to individual symptoms between community-dwelling older adults with dementia and their nursing home counterparts after controlling for dementia severity and medication use, and explore risk predictors of clinically significant symptoms and moderate-to-severe caregiver distress caused in the target population.

The study included 157 community-dwelling older adults with dementia [age: 76.8 ± 9.9 (range 60–94) years; female: 93 (59.2%)] and 112 nursing home residents with dementia [age: 81.2 ± 8.1 (range 60–97) years; female: 41 (36.6%)]. Of those living in the community, 71 (45.5%) were cared for by their children, 64 (40.8%) by their spouse, and 22 (14%) by other relatives. The family caregivers spent an average of 12.2 ± 6.3 h per day providing supervision and caregiving. The demographic and clinical characteristics of the participants are shown in Table 1. The community patients were younger, with higher BI scores, and less severe dementia than the nursing home patients. They were also more likely to use anxiolytics, anti-depressants, and anticonvulsants (Table 1).

In this study, community-dwelling older adults with dementia showed more frequent clinically significant BPSD than nursing home patients, and these caused more severe caregiver distress. This was especially true for those with moderate-to-severe dementia. After controlling for dementia severity and medication use, family caregiving remained an independent risk predictor for presenting clinically significant symptoms and moderate-to-severe caregiver distress. The prediction of caregiver distress based on symptom severity varied across caregiver types. The strength of this study is that our findings were controlled for dementia severity and medication used by participants. Our findings add to the growing understanding of BPSD and caregiver distress they cause in low- and middle-income countries.

Clinically significant symptoms were found in 88.5% of community-dwelling older adults with dementia and 75% of nursing home patients in this study. After controlling for dementia severity and medication use, we found that caregiver type remained an independent risk predictor for presenting clinically significant BPSD. One potential explanation is that BPSD rely on caregiver proxies to report, and family caregivers may have more opportunities to observe these symptoms. Moreover, family caregivers might be more involved in affective disturbances of care recipients, and the internalizing symptoms of dementia, such as anxiety and depression, might be over-reported by family caregivers because of their increased risks for stress, depression, and burden. Another explanation is that formal caregivers are more likely to have had some training in managing BPSD (34). Training has been found to have an impact on the way staff behave toward residents with dementia (35). Family caregivers’ improper management of behavior problems might result in aggravation of the symptoms (36). Delivery appropriate training to caregivers has been proposed as a key component of good dementia care (34).

Impressively, up to 70% of the community-dwelling older adults with dementia had at least one symptom causing severe caregiver distress in this study. However, only 9.8% of the nursing home residents with dementia had at least one symptom causing severe caregiver distress. Family caregivers caring for community-dwelling older adults with dementia experienced more severe distress caused by symptoms than formal caregivers caring for nursing home residents with dementia. After controlling for symptom severity, family caregiving remaining an independent risk predictor for moderate-to-severe caregiver distress in this study, especially eating disorders and anxiety. One explanation is that family caregivers provide longer company for care recipients and undertake additional caregiving tasks than formal caregivers, while formal caregivers are more likely to work cooperatively to manage patients in their workplace than family caregivers. Another explanation is that there is currently insufficient quality and quantity of family based care services in China to meet the needs of community-dwelling older adults with dementia (2). Family caregivers may therefore experience a higher level of distress due to the lack of resources and support in the public health care system to manage and treat dementia symptoms (18).

Previous studies suggest that information on caregiver distress caused by individual symptoms is crucial to inform the design of tailored management strategies for supporting family caregivers (6, 15, 37). In this study, agitation and sleep disorders were the fifth and sixth frequent of “very severe” symptom but caused the most frequent “very severe” distress to family caregivers caring for community-dwelling older adults with dementia. However, the community-dwelling patients had a similar prevalence of agitation during the moderate stage of dementia, compared with their nursing home counterparts. Agitation is one of the most common symptoms across studies (6, 7, 37, 38). In the context of biopsychosocial approaches (36, 39, 40), agitation often occurs during personal care, and may be closely linked to expressions of unmet need (e.g., can be aggressive if attention is not given) and inadequate interactions between caregivers and care recipients (41). Sleep disorders in patients with dementia include fragmented sleep at night, daytime sleepiness, inversion of the sleep-wake cycle, and sleep behavior disorders (42). Various factors, such as the need to urinate during the night, brain stimulants (coffee and bronchodilators), pain, and medications (diuretics), may contribute to sleep disorders (43). Family caregivers have more exposure to care recipients at night (42, 44), and sleep disorders can therefore cause or exacerbate sleep deprivation and exhaustion in family caregivers. We also found that euphoria was more prevalent and clinically significant, but had no difference in the distress for caregivers of community patients with severe dementia, compared with the nursing home patients. Our findings should encourage healthcare providers to focus on clinically significant symptoms that produce severe distress in family caregivers, rather than those that are more prevalent. Similarly, a recent study suggests that clinicians should distinguish relatively untroubling symptoms from more exhausting symptoms (37).

In this study, community-dwelling older adults with dementia had more than ten times the risk of presenting clinically significant anxiety and depression, which causing five to ten times the risk of moderate-to-severe distress to family caregivers. Affective disturbances should be taken into account in alleviating distress for family caregivers. We also found that the severity of euphoria and disinhibition did not strongly predict caregiver distress caused in community-dwelling older adults, while the severity of eating disorders did not strongly predict caregiver distress caused in nursing home residents with dementia. Euphoria and disinhibition, which have been classified as “Frontal” endophenotype (45), were the rarest symptoms in both this study and previous studies (37, 45, 46). A recent study suggests that sexual disinhibition appears to be a particularly difficult symptom for the family caregiver (47). However, there were 125 (11.8%) FTD patients in that study, but only 2 (1.3%) FTD patients in this study. The low prevalence of euphoria and disinhibition might partially contribute to the low prediction of caregiver distress caused in this study. Formal caregivers may be more likely to cooperate with colleagues, and be less involved in providing daily care (such as support with eating). Therefore, eating disorders may not place such a physical and psychological burden on formal caregivers. Our findings suggest that intervention strategies for reducing caregiver distress caused by BPSD should consider caregiver types and individual symptoms.

From a public health perspective, optimizing dementia care in the home may provide the maximum population-level benefit (such as decreasing the huge economic costs associated with transitions to other care settings) and is desirable given the preference of older people to remain in their familiar communities for as long as possible (48). The majority of older people with dementia live at home with unpaid family caregivers, and these family caregivers are at risk for poor physical, mental, emotional, and socioeconomic outcomes (49). The present study found that family caregivers caring for community-dwelling older people with dementia were exposed to more frequent clinically significant and moderate-severe distressing BPSD than formal caregivers (nursing home staff). BPSD are the most treatable aspects of dementia and might be alleviated or eliminated through comprehensive interventions to target contributing factors or triggers (34). There are complex overlaps or interplay of reactive, responsive, and/or organic causes of BPSD (50). Caregiver factors are some of the causes and triggers of BPSD (36), for example, inadequate interactions between caregivers and care recipients may contribute to the occurrence or exacerbation of BPSDs. Reciprocally, exacerbation of BPSD may aggravate caregiver distress (15). Training and supporting family caregivers, especially for proper management of BPSD may help to break this vicious circle. Our findings suggest that an effective support service system should be established to give family caregivers access to resources, information, and knowledge to improve their ability to cope with BPSD. The support service system, such as Dementia Support programs proposed in Australia (51), might enable people with dementia to stay at home longer.

This study had several limitations. First, the cross-sectional design of this study does not allow for a test of causal relationships. Second, modest sample size and insufficient information on dementia subtypes limited further analysis. Third, our data were collected from family caregivers who voluntarily visited the outpatient clinic of a tertiary psychiatric hospital, which may have introduced referral bias. Fourth, the study did not investigate factors related to caregiver burden or mental health status (such as depression and anxiety). The above-mentioned factors might limit the generalizability of our findings. Future studies with a larger sample size should consider these factors.

This study found that family caregivers experienced more severe distress caused by behavioral and psychological symptoms of dementia than formal caregivers; family caregiving was an independent risk predictor for clinically significant and moderate-to-severe distressing symptoms; the prediction of caregiver distress based on symptom scores varied by individual symptoms and caregiver types. Our findings highlight that tailored management strategies are needed to relieve family caregivers’ distress caused by BPSD, and that an effective support service system should be established to give family caregivers access to resources, information, and knowledge to improve their ability to cope with BPSD.

The original contributions presented in the study are included in the article/Supplementary Material, further inquiries can be directed to the corresponding author.

The studies involving human participants were reviewed and approved by The Ethics Committee of Nanfang Hospital (No. NFEC-201511-K2) approved this study. The patients/participants provided their written informed consent to participate in this study.

XJL, JW, and RY gathered the data, completed the data analysis and interpretation, and took part in drafting of the manuscript. DR helped with acquisition of data and clinical diagnosis. XYL advised on the design of the study, secured funding, supervised the research, took responsibility for the accuracy of the data analysis and interpretation, and provided critical and substantive commentary to both the process and final product. All authors granted approval for submission and publication, contributed to revising the manuscript critically for important intellectual content, and were in agreement with the content of the manuscript.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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