Abstract
Aim
This study investigated the association between lifestyle habits and the risk of depression among people living with someone needing care in Japan.
Methods
Data were collected from those who participated in the Yamagata Cohort Study; 11 019 participants aged 40 and above were considered. The primary endpoints were living with someone in need of care and depression risk, and individual factors related to these endpoints were examined. Unadjusted and multifactor‐adjusted logistic regression analyses were conducted to examine the association between the risk of depression and personal factors among those living with someone needing care.
Results
Of the participants, 942 (8.5%) were living with someone who needed care. The proportion of participants who were at risk for depression was significantly higher among those living with someone needing care; this group also had significantly higher odds ratios than those at low risk of depression for the following factors: economic comfort: hardship; sleep duration: more than 9 h; getting enough sleep, including nights and naps: not enough; go out at least once a week: no; and walking or equivalent physical activity in daily life for at least 1 h a day: no.
Conclusion
To reduce the risk of depression among family caregivers, providing them with appropriate social and financial support is crucial. Geriatr Gerontol Int 2025; 25: 1503–1510.
Keywords: care, depression, family caregivers, lifestyle, Yamagata Cohort Study
The present study found that living with someone in need of care increases the risk of depression in Japan. Key associated factors include economic hardship, insufficient sleep, low physical activity, and infrequent socializing. In order to reduce the risk of depression among family caregivers, it is crucial that appropriate social and financial support is provided.
Introduction
The percentage of the Japanese population aged 65 and over reached a record high of 29.1% in 2023, highlighting Japan's status as a super‐aged society. 1 The number of people aged 65 and over is expected to decline after 2050, but as a proportion of the total population, it is expected to continue to rise to 38.7% by 2070. 2 According to the 2021 Care Insurance Business Status Report, the number of persons requiring care or support was 6.9 million, 18.9% of whom were 65 years or above. 3 The demand for medical and long‐term care is expected to increase with population aging, and the number of people receiving care at home is increasing accordingly. In 2021, an average of 5.89 million people were care insurance service recipients monthly; of these, 4.05 million (68.7%) were home care service recipients. 3 In home medical care, family caregivers play a major role. Consequently, the burden of caregiving on family caregivers has become an issue.
Studies have reported that the provision of care negatively impacts subjective well‐being 4 and that family caregivers have higher levels of psychological distress 5 and a higher risk of death. 6 Spouse caregivers reportedly experience more symptoms of depression, greater financial and physical burdens, and lower psychological well‐being than non‐spouse caregivers. 7 However, it was found that family caregivers did not differ from non‐caregivers with respect to diseases such as cancer, stroke, heart disease, and diabetes, 8 and no difference was observed in mortality risk between family caregivers and non‐caregivers, 9 with family caregivers having a lower mortality risk. 10 Thus, while it is clear that caregiving increases the physical and mental burden on family caregivers, there is no consensus on the impact of caregiving on health.
Previous research has focused mainly on caregiver burden, 4 , 5 , 6 , 7 whereas relatively few studies have explored lifestyle habits that may be associated with the positive aspects of caregiving, such as lower mortality risk. However, a healthy lifestyle helps maintain mental health and prevents depression in the general population. 11 Given that caregiving can involve both stress and personal growth, it is essential to investigate whether certain lifestyle habits buffer the negative impacts and promote well‐being. Identifying these modifiable factors is important for developing more effective interventions, such as psychoeducation, respite care, and psychotherapy, to help caregivers maintain their mental health. This study, thus, aimed to clarify the association between lifestyle habits and the risk of depression among people living with someone in need of care, using data from the Yamagata Cohort Study.
Methods
Participants
The Yamagata Cohort Study was conducted as part of the Global Center of Excellence (COE) Program “Establishment of an International Education and Research Network in Molecular Epidemiology.” 12 , 13 Written informed consent was obtained from all participants, and the study was conducted in accordance with the Declaration of Helsinki.
The target population comprised individuals aged 40 and older who participated in a community‐based annual health checkup conducted in seven cities in Yamagata Prefecture (Yamagata, Sakata, Kaminoyama, Sagae, Higashine, Tendo, and Yonezawa). There were no exclusion criteria. A total of 20 969 respondents took part in the baseline survey from 2009 to 2015. An additional cross‐sectional survey was conducted in 2021 among 17 527 participants from the 2009–2015 baseline survey (3442 participants who had died or moved were excluded), and responses were obtained from 12 216 individuals (69.7% response rate). In this study, 11 019 valid responses were analyzed, after excluding 1197 responses with missing information.
Analysis items
Items were extracted from the Questionnaire on Health and Lifestyle Habits distributed in the additional survey questionnaire, the participants' most recent health checkup results, and the Specific Health Examination Questionnaire.
The primary endpoints were caregiving status and depression risk. Regarding caregiving status, participants were asked: “Do you currently live with someone who requires care?” Those who answered yes were defined as living with someone in need of care, and those who answered no were defined as not living with someone in need of care. The former group was further categorized based on their relationship with the person in need of care: spouse, parent, and/or other. The time spent per day on care was classified into three categories: 1 h, 2 to 3 h, and more than 4 h.
Depression risk was determined using the depression risk criteria of the Kihon Checklist, 14 based on the Care Insurance Act. The Kihon Checklist is used to identify older adults who are at risk of declining in terms of their daily living functions at an early stage, and to link them to social resources. 15 Depression risk was determined by whether participants answered yes or no to the following five questions regarding the previous 2 weeks: “Have you felt a lack of fulfillment in your daily life?”, “Have you felt a lack of joy when doing the things you used to enjoy?”, “Have you felt difficulty in doing what you could do easily before?”, “Have you felt helpless?”, “Have you felt tired without a reason?” If a participant answered yes to two or more of the questions, they were considered to be at risk for depression. 15
We focused on basic attributes, social factors, and lifestyle as individual aspects related to caregiving status and depression risk. Basic attributes included age and gender. Age was classified into three groups: 40 to 65, 65 to 75, and over 75 years. Social factors included education, employment, household income, and economic comfort. Education was categorized into three groups: elementary and middle school, high school, and university/higher education, while employment was categorized into two groups: employed and unemployed/housewife/househusband. Household income was classified into four categories: 0 to 2.99 million yen, 3 to 5.99 million yen, 6 to 8.99 million yen, and ≥9 million yen. Economic comfort regarding living conditions on current income was classified into three categories: hardship, normal, and comfortable.
Lifestyle was analyzed in terms of body mass index (BMI), history of hypertension, diabetes, and hyperlipidemia, smoking, drinking alcohol, sleep, frequency of going out, and exercise. Hypertension was defined as having at least one of the following conditions: systolic blood pressure of ≥140 mmHg, diastolic blood pressure of ≥90 mmHg, or taking antihypertensive medication. Diabetes was defined as one or more of the following: fasting blood glucose of ≥126 mg/dL, HbA1c (NGSP) of ≥6.5%, or taking insulin injections or hypoglycemic drugs. Hyperlipidemia was defined as total cholesterol ≥220 mg/dL, triglycerides (triglycerides) ≥ 150 mg/dL, or taking medication to treat hyperlipidemia. Smoking was categorized into yes and no, and drinking was categorized into every day, sometimes, and never. Sleep duration was classified into three groups: less than 6 h, 7 to 8 h, and more than 9 h. The item “get enough sleep, including nights and naps” was classified into two groups: enough and not enough. The frequency of going out was categorized as going out at least once a week, and exercise was categorized into yes or no based on the response to the item: “walking or equivalent physical activity in daily life for at least one hour a day.”
Statistical analysis
Participants' individual factors were compared in terms of whether or not they lived with someone in need of care and whether or not those living with someone in need of care were at risk of depression. For each analysis item, means and standard deviations were calculated for continuous variables; categorical variables were calculated as a percentage of the total number of respondents. Continuous variables were subjected to t‐tests, and categorical variables to χ2 tests.
Unadjusted and multifactor‐adjusted logistic regression analyses were conducted to examine the association between personal factors and the risk of depression among those living with a person in need of care. In the multifactor‐adjusted analysis, the following adjustment factors were used: age; gender; family income; economic comfort; relationship to care recipient; time spent on caregiving; sleep duration; sleep quality, including nights and naps; going out at least once a week; and walking or equivalent physical activity in daily life for at least 1 h a day. JMP Pro17 for Windows (JMP Statistical Discovery LLC; Cary, NC) was used for these analyses. The statistical significance level was set at P < 0.05.
Results
Comparison of individual factors according to whether or not the participant lives with someone who needs care
Table 1 compares the participants' factors according to whether or not they lived with someone needing care. Among the participants, 942/11019 (8.5%) were living with someone needing care, and 10 077 (91.5%) were not. Among male respondents (n = 4367), 334 (7.6%) lived with someone needing care. Among female respondents (n = 6652), 608 (9.1%) lived with someone needing care. Overall, the proportion of women who lived with someone needing care was significantly higher than those who did not (P = 0.007). The overall mean age for participants who lived with someone needing care was 70.5 (SD = 0.3) years, and it was 72.1 (SD = 0.1) years for those not living with someone needing care. The mean age of the former group was significantly lower than that of the other group (P < 0.001).
Table 1.
Comparison of individual factors according to whether or not the person lives with someone who needs care
| Living with someone needing care n = 942 (8.5%) | Not living with someone needing care n = 10 077 (91.5%) | P‐value | |||
|---|---|---|---|---|---|
| n | % | n | % | ||
| Age mean (SD) | 70.5 | (0.3) | 72.1 | (0.1) | <0.001** |
| 40–64 years old | 224 | 23.8 | 1578 | 15.7 | <0.001** |
| 65–74 years old | 391 | 41.5 | 4275 | 42.4 | |
| ≥ 75 years old | 327 | 34.7 | 4224 | 41.9 | |
| Gender | 0.007** | ||||
| Male | 334 | 35.5 | 4033 | 40.0 | |
| Female | 608 | 64.5 | 6044 | 60.0 | |
| Academic background | 0.025* | ||||
| Elementary and middle school | 89 | 10.0 | 1215 | 12.8 | |
| High school | 491 | 55.3 | 5304 | 55.7 | |
| University and higher education | 308 | 34.7 | 3007 | 31.6 | |
| Employment | 0.154 | ||||
| Employed | 355 | 37.7 | 3562 | 35.6 | |
| Unemployed/housewife/househusband | 587 | 62.3 | 6511 | 64.6 | |
| Household income | 0.001** | ||||
| 0–2.99 million yen | 363 | 42.5 | 4370 | 48.3 | |
| 3–5.99 million yen | 329 | 38.5 | 3356 | 37.1 | |
| 6–8.99 million yen | 97 | 11.3 | 800 | 8.8 | |
| ≥ 9 million yen | 66 | 7.7 | 528 | 5.8 | |
| Economic comfort | 0.040* | ||||
| Hardship | 311 | 34.0 | 2947 | 30.2 | |
| Normal | 504 | 55.1 | 5781 | 59.2 | |
| Comfortable | 99 | 10.8 | 1030 | 10.6 | |
| BMI mean (SD) | 23.0 | (0.1) | 23.2 | (0.0) | 0.363 |
| <18.5 | 47 | 6.6 | 474 | 6.1 | 0.327 |
| 18.5–24.9 | 495 | 69.1 | 5215 | 67.3 | |
| 25–29.9 | 150 | 21.0 | 1840 | 23.8 | |
| ≥ 30 | 24 | 3.4 | 216 | 2.8 | |
| Hypertension | 393 | 54.9 | 4595 | 59.2 | 0.026* |
| Diabetes | 87 | 12.2 | 1080 | 13.9 | 0.212 |
| Hyperlipidemia | 384 | 53.6 | 4116 | 53.1 | 0.784 |
| Smoking | 58 | 8.1 | 577 | 7.4 | 0.505 |
| Drinking alcohol | 0.873 | ||||
| Every day | 161 | 22.6 | 1806 | 23.4 | |
| Sometimes | 168 | 23.6 | 1780 | 23.1 | |
| No (cannot drink) | 384 | 53.9 | 4132 | 53.5 | |
| Sleep duration | <0.001** | ||||
| ≤ 6 h | 267 | 29.9 | 2079 | 21.6 | |
| 7–8 h | 565 | 63.3 | 6783 | 70.4 | |
| ≥ 9 h | 60 | 6.7 | 774 | 8.0 | |
| Get enough sleep, including nights and naps | 497 | 53.0 | 6700 | 67.1 | <0.001** |
| Go out at least once a week | 878 | 93.7 | 9387 | 93.8 | 0.887 |
| Walking or equivalent physical activity in daily life for at least 1 h a day | 221 | 32.4 | 2612 | 35.0 | 0.179 |
| Feel a lack of fulfillment in your daily life | 192 | 20.7 | 1362 | 13.7 | <0.001** |
| Feel a lack of joy when doing the things you used to enjoy | 141 | 15.2 | 969 | 9.7 | <0.001** |
| Feel difficulty in doing what you could do easily before | 223 | 23.9 | 1733 | 17.4 | <0.001** |
| Feel helpless | 110 | 11.9 | 1110 | 11.2 | 0.514 |
| Feel tired without a reason | 233 | 25.1 | 1708 | 17.1 | <0.001** |
| At risk for depression | 242 | 26.5 | 1767 | 18.0 | <0.001** |
| Relationship with the care recipient | |||||
| Spouse | 333 | 36.2 | |||
| Parent | 423 | 45.9 | |||
| Other (children, siblings, grandchildren, etc.) | 165 | 17.9 | |||
| Time spent caring (h/day) mean (SD) | 3.5 | (0.2) | |||
| 1 h | 259 | 39.6 | |||
| 2–3 h | 210 | 32.1 | |||
| ≥ 4 h | 185 | 28.3 | |||
Continuous variable: t‐test. Categorical variable: χ 2 test.
P < 0.05.
P < 0.01.
Regarding the depression risk assessment, the percentage of respondents was significantly higher in the “living with” group than in the “not living with” group for four of the five items, except for “feel helpless.” The proportion of those who were classified as at risk of depression for two or more of the five items was also significantly higher for those “living with” than for those “not living with” (P < 0.001).
Comparison of individual factors with regard to the presence or absence of depression risk among those living with someone who needs care
The individual factors of the participants were compared with regard to the presence or absence of depression risk among those living with a person in need of care (Table 2). Among those who lived with someone needing care, 242 (26.5%) were at risk for depression and 672 (73.5%) were not.
Table 2.
Comparison of individual factors with regard to the presence or absence of depression risk among those living with someone who needs care
| Living with a person in need of care | |||||
|---|---|---|---|---|---|
| At risk for depression n = 242 (26.5%) | Not at risk for depression n = 672 (73.5%) | P‐value | |||
| n | % | n | % | ||
| Age mean (SD) | 71.4 | (0.5) | 70.0 | (0.3) | 0.031* |
| 40–64 years old | 56 | 23.1 | 166 | 24.7 | 0.002** |
| 65–74 years old | 82 | 33.9 | 299 | 44.5 | |
| ≥ 75 years old | 104 | 43.0 | 207 | 30.8 | |
| Gender | 0.434 | ||||
| Male | 91 | 37.6 | 233 | 34.7 | |
| Female | 151 | 62.4 | 439 | 65.3 | |
| Academic background | 0.071 | ||||
| Elementary and middle school | 28 | 12.2 | 56 | 8.9 | |
| High school | 134 | 58.3 | 340 | 53.9 | |
| University and higher education | 68 | 29.6 | 235 | 37.2 | |
| Employment | 0.064 | ||||
| Employed | 79 | 32.6 | 265 | 39.4 | |
| Unemployed/housewife/househusband | 163 | 67.4 | 407 | 60.6 | |
| Household income | 0.021* | ||||
| 0–2.99 million yen | 108 | 48.6 | 240 | 39.5 | |
| 3–5.99 million yen | 84 | 37.8 | 240 | 39.5 | |
| 6–8.99 million yen | 21 | 9.5 | 72 | 11.8 | |
| ≥ 9 million yen | 9 | 4.1 | 56 | 9.2 | |
| Economic comfort | <0.001** | ||||
| Hardship | 111 | 47.4 | 189 | 29.0 | |
| Normal | 106 | 45.3 | 384 | 58.9 | |
| Comfortable | 17 | 7.3 | 79 | 12.1 | |
| Relationship with care recipient | 0.015* | ||||
| Spouse | 99 | 42.5 | 223 | 33.7 | |
| Parent | 89 | 38.2 | 324 | 48.9 | |
| Other (children, siblings, grandchildren, etc.) | 45 | 19.3 | 115 | 17.4 | |
| Time spent caring (h/day) mean (SD) | 4.2 | (0.4) | 3.3 | (0.2) | 0.017* |
| 1 h | 51 | 31.3 | 204 | 42.6 | 0.023* |
| 2–3 h | 55 | 33.7 | 150 | 31.3 | |
| ≥ 4 h | 57 | 35.0 | 125 | 26.1 | |
| BMI mean (SD) | 23.5 | (0.3) | 22.9 | (0.1) | 0.062 |
| <18.5 | 10 | 5.8 | 36 | 6.9 | 0.218 |
| 18.5–24.9 | 112 | 64.7 | 368 | 70.8 | |
| 25–29.9 | 42 | 24.3 | 101 | 19.4 | |
| ≥ 30 | 9 | 5.2 | 15 | 2.9 | |
| Hypertension | 105 | 60.7 | 274 | 52.7 | 0.078 |
| Diabetes | 27 | 15.6 | 58 | 11.2 | 0.141 |
| Hyperlipidemia | 96 | 55.5 | 274 | 52.7 | 0.539 |
| Smoking | 13 | 7.5 | 45 | 8.7 | 0.752 |
| Drinking alcohol | 0.331 | ||||
| Every day | 46 | 26.9 | 112 | 21.5 | |
| Sometimes | 40 | 23.4 | 124 | 23.8 | |
| No (cannot drink) | 85 | 49.7 | 284 | 54.6 | |
| Sleep duration | <0.001** | ||||
| ≤ 6 h | 76 | 34.2 | 186 | 28.8 | |
| 7–8 h | 119 | 53.6 | 429 | 66.5 | |
| ≥ 9 h | 27 | 12.2 | 30 | 4.7 | |
| Get enough sleep, including nights and naps | 101 | 42.1 | 380 | 56.6 | <0.001** |
| Go out at least once a week | 216 | 90.0 | 640 | 95.4 | 0.004** |
| Walking or equivalent physical activity in daily life for at least one hour a day | 41 | 24.8 | 175 | 35.1 | 0.016* |
Continuous variable: t‐test. Categorical variable: χ2 test.
P < 0.05.
P < 0.01.
The mean age for those at risk of depression was 71.4 (SD = 0.5) years and it was 70.0 (SD = 0.3) years for those not at risk for depression. Significant differences were found in social factors of “household income” (P = 0.021), “economic comfort” (P < 0.001), “primary relationship with the care recipient” (P = 0.015), and “caregiving time” (P = 0.017). Significant differences were also observed in the four lifestyle items of sleep duration (P < 0.001); getting enough sleep, including nights and naps (P < 0.001); going out at least once a week (P = 0.004); and walking or equivalent physical activity in daily life for at least 1 h a day (P = 0.016) depending on whether the participants were at risk of depression.
Relationship between depression risk and individual factors in those living with someone who needs care
Unadjusted and multifactor‐adjusted logistic regression analyses were conducted to examine individual factors associated with the presence or absence of depression risk among those living with a person in need of care (Table 3).
Table 3.
Relationship between depression risk and individual factors in those living with someone who needs care
| Model 1 | P‐value | Model 2 | P‐value | |||
|---|---|---|---|---|---|---|
| OR | 95% CI | OR | 95% CI | |||
| Age mean (SD) | ||||||
| 40–64 years old | 1.00 | 1.00 | ||||
| 65–74 years old | 0.78 | 0.41–1.47 | 0.441 | 1.27 | 0.40–4.03 | 0.687 |
| ≥ 75 years old | 1.37 | 0.50–3.76 | 0.535 | 2.84 | 0.45–17.89 | 0.267 |
| Gender | ||||||
| Male | 1.00 | 1.00 | ||||
| Female | 0.88 | 0.65–1.19 | 0.414 | 0.96 | 0.53–1.74 | 0.894 |
| Academic background | ||||||
| Elementary and middle school | 1.00 | 1.00 | ||||
| High school | 0.79 | 0.48–1.29 | 0.347 | 1.04 | 0.33–3.26 | 0.940 |
| University and higher education | 0.58 | 0.34–0.98 | 0.042* | 0.85 | 0.25–2.84 | 0.787 |
| Employment | ||||||
| Employed | 1.00 | 1.00 | ||||
| Unemployed/housewife/househusband | 1.34 | 0.99–1.83 | 0.062 | 0.71 | 0.38–1.33 | 0.279 |
| Household income | ||||||
| 0–2.99 million yen | 1.00 | 1.00 | ||||
| 3–5.99 million yen | 0.78 | 0.56–1.09 | 0.143 | 1.38 | 0.77–2.49 | 0.281 |
| 6–8.99 million yen | 0.65 | 0.38–1.11 | 0.113 | 2.48 | 0.91–6.78 | 0.077 |
| ≥ 9 million yen | 0.36 | 0.17–0.75 | 0.006** | 0.38 | 0.08–1.82 | 0.226 |
| Economic comfort | ||||||
| Hardship | 2.13 | 1.55–2.92 | <0.001** | 2.47 | 1.40–4.37 | 0.002** |
| Normal | 1.00 | 1.00 | ||||
| Comfortable | 0.78 | 0.44–1.37 | 0.389 | 0.87 | 0.31–2.47 | 0.796 |
| Relationship with the care recipient | ||||||
| Spouse | 1.00 | 1.00 | ||||
| Parent | 0.62 | 0.44–0.86 | 0.005** | 0.77 | 0.37–1.60 | 0.485 |
| Others (children, siblings, grandchildren, etc.) | 0.88 | 0.58–1.34 | 0.554 | 1.11 | 0.51–2.41 | 0.785 |
| Time spent caring (h/day) mean (SD) | ||||||
| 1 h | 1.00 | 1.00 | ||||
| 2–3 h | 1.47 | 0.95–2.27 | 0.085 | 1.05 | 0.55–2.03 | 0.877 |
| ≥ 4 h | 1.82 | 1.18–2.83 | 0.007** | 1.88 | 0.97–3.65 | 0.062 |
| BMI | ||||||
| <18.5 | 0.91 | 0.44–1.90 | 0.807 | 0.67 | 0.23–1.98 | 0.474 |
| 18.5–24.9 | 1.00 | 1.00 | ||||
| 25–29.9 | 1.37 | 0.90–2.07 | 0.143 | 1.25 | 0.65–2.40 | 0.498 |
| ≥ 30 | 1.97 | 0.84–4.63 | 0.119 | 1.06 | 0.27–4.18 | 0.934 |
| Hypertension | ||||||
| No | 1.00 | 1.00 | ||||
| Yes | 1.39 | 0.98–1.97 | 0.068 | 1.16 | 0.66–2.05 | 0.613 |
| Diabetes | ||||||
| No | 1.00 | 1.00 | ||||
| Yes | 1.47 | 0.90–2.41 | 0.124 | 1.68 | 0.75–3.74 | 0.208 |
| Hyperlipidemia | ||||||
| No | 1.00 | 1.00 | ||||
| Yes | 1.12 | 0.79–1.58 | 0.523 | 0.97 | 0.56–1.67 | 0.902 |
| Smoking | ||||||
| Yes | 0.86 | 0.45–1.63 | 0.640 | 1.37 | 0.40–4.78 | 0.617 |
| No | 1.00 | 1.00 | ||||
| Drinking alcohol | ||||||
| Every day | 1.37 | 0.90–2.09 | 0.140 | 1.48 | 0.65–3.35 | 0.347 |
| Sometimes | 1.08 | 0.70–1.66 | 0.733 | 1.32 | 0.70–2.48 | 0.395 |
| No (cannot drink) | 1.00 | 1.00 | ||||
| Sleep duration | ||||||
| ≤ 6 h | 1.00 | 1.00 | ||||
| 7–8 h | 0.68 | 0.49–0.95 | 0.024* | 1.56 | 0.82–2.96 | 0.176 |
| ≥ 9 h | 2.20 | 1.23–3.95 | 0.008** | 9.12 | 2.51–33.1 | 0.001** |
| Get enough sleep, including nights and naps | ||||||
| Enough | 1.00 | 1.00 | ||||
| Not enough | 1.80 | 1.33–2.42 | <0.001** | 2.97 | 1.60–5.52 | 0.001** |
| Go out at least once a week | ||||||
| Yes | 1.00 | 1.00 | ||||
| No | 2.29 | 1.32–3.99 | 0.003** | 3.60 | 1.33–9.76 | 0.012* |
| Walking or equivalent physical activity in daily life for at least 1 h a day | ||||||
| Yes | 1.00 | 1.00 | ||||
| No | 1.64 | 1.10–2.44 | 0.015* | 1.84 | 1.02–3.32 | 0.043* |
Adjustment factor. Model 1: Unadjusted. Model 2: Age; Gender; Household income; Economic comfort; Relationship with care recipient; Time spent caring; Sleep duration; Getting enough sleep, including nights and naps; Go out at least once a week; and Walking or equivalent physical activity in daily life for at least 1 h a day. Logistic regression analysis *: P < 0.05, **: P < 0.01.
CI, confidence interval; OR, odds ratio.
In the multifactor adjustment model for basic attributes and social factors, significant differences were found in economic comfort: hardship, odds ratio (OR) = 2.47, 95% confidence interval (CI) (1.40–4.37), P = 0.002, vs. normal.
In the multifactor‐adjusted model, significant differences were found in the following lifestyle items: sleep duration: ≥ 9 h, OR = 9.12, 95% CI (2.51–33.1), P = 0.001, vs. ≤ 6 h; getting enough sleep, including nights and naps: not enough, OR = 2.97, 95% CI (1.60–5.52), P = 0.001, vs. enough; going out at least once a week: no, OR = 3.60, 95% CI (1.33–9.76), P = 0.012, vs. yes; and walking or equivalent physical activity in daily life for at least 1 h a day: no, OR = 1.84, 95% CI (1.02–3.32), P = 0.043, vs. yes.
Discussion
This study examined the relationship between lifestyle and depression risk in participants of the Yamagata Cohort Study and whether or not they lived with someone in need of care. The results showed that the risk of depression was higher among those who lived with someone in need of care and that this group reported more economic hardship, lower sleep satisfaction, and more difficulties in their daily activities than those at lower risk of depression.
The target population in this study had a slightly lower percentage of caregivers than in previous studies. 4 , 5 , 8 , 9 , 10 The average age in these previous studies ranged from 45.0 to 68.7 years for family caregivers and from 42.2 to 72.6 years for those who were not family caregivers, 4 , 8 , 9 , 10 suggesting that the higher age of the target population in this study compared with previous studies resulted in a slightly lower percentage of caregivers. In terms of gender, this study had a higher proportion of female caregivers, similar to the results reported in previous studies. 8 , 9 , 16 , 17
In the depression risk assessment of those living with someone who needs care, the percentage of those at risk of depression was significantly higher for those living with someone who needs care than for those who were not. Previous studies using the Kessler 6 (K6) 18 , 19 and European‐Depression (EURO‐D) scale 20 revealed that family caregivers have a higher level of psychological distress. 5 , 8 The criteria used in this study also indicate a higher risk of depression among those who live with someone who needs care; we believe that the results support the importance of emotional support for family caregivers, as in previous studies.
Although living with someone who needs care increases the risk of depression, not everyone in this situation is at risk of depression. Therefore, we examined the relationship between the risk of depression and individual factors. The results showed that the following factors increased the risk of depression: economic comfort: hardship; sleep duration: ≥ 9 h; getting enough sleep, including nights and naps: not enough; going out at least once a week: no; and walking or equivalent physical activity in daily life for at least 1 h a day: no.
Regarding economic aspects, the 2023 Household Budget Survey 21 indicated that among households with two or more members, the proportion of expenditures for healthcare is 1.6 times higher for those in which the head of the household is 65 years or older than for other households. Similarly, Saito et al. show that family caregivers with depressive symptoms have significantly lower household incomes than those without. 22 In this study, we believe that the difference in perception of financial hardship rather than household income should be considered, because even with some income, high expenditures related to medical care and long‐term care may have led to the perception of financial hardship. In supporting family caregivers, it is important to focus on household income, spending conditions, and perceptions of financial comfort.
With regard to lifestyle habits, Longobardo et al. found that family caregivers were significantly more likely to have sleep disturbances than those who were not family caregivers. 8 Because differences in the perception of lack of sleep sufficiency were also observed in this study, it is necessary to pay particular attention to sleep in the healthcare of family caregivers. Furthermore, it is important not only to ensure sleep‐resting time but also to provide support to increase sleep satisfaction. The significant difference in the “sleep duration: ≥ 9 hours” category may be influenced by the small number of respondents (n = 57), which limits the statistical power and generalizability. Causality cannot be determined; therefore, longitudinal studies are needed to clarify the relationship. Oldenkamp et al. evaluated family caregivers using the CarerQoL‐7D (Care‐Related Quality of Life instrument), an index of care‐related quality of life, and identified five negative aspects: relational problems with the care recipient, mental health problems, difficulties combining daily activities, financial problems, and physical health problems. The most frequent issue was difficulties combining daily activities, followed by physical health problems. 23 This study also showed that family caregivers have problems with their usual activities, such as going out and exercising. These findings suggest that it is important to support family caregivers to ensure that they can carry out roles other than caregiving and have time for themselves by introducing and adjusting social resources.
This study suggests the importance of financial support for family caregivers, support to increase sleep satisfaction, and support to allow them time for other activities. However, further intervention studies are needed to determine the extent to which these forms of support contribute to reducing the risk of depression among family caregivers.
Several limitations must be considered in this study. First, detailed information on the care recipients’ condition, cognitive function, activities of daily living status, level of required care, use of nursing care services, and duration of care was lacking. Additionally, our definition of caregiving—living with someone who needs care—may not reflect actual caregiving involvement, possibly leading to a misclassification bias. Some who were classified as caregivers might not have provided care, whereas others offering support outside the home were excluded. This could have led to an underestimation of the psychological impact of caregiving. Future studies should use more precise measures of caregiving roles and intensity to better capture these associations. Second, although the Kihon Checklist has been shown to predict the incidence of functional decline in older adults, 24 it has not been specifically designed for depression. Therefore, for a more accurate assessment of depression risk, validated, standardized scales such as the Patient Health Questionnaire‐9 (PHQ‐9) 25 or Center for Epidemiologic Studies Depression (CES‐D) 26 must be used. Third, the participants received health checkups in the community and may have been more health‐conscious than the general population, which may have caused a selection bias in the participants. In addition, because this study is based on data from the Yamagata Prefecture Cohort Study, it may have been influenced by regional characteristics, such as the social and cultural background of Yamagata Prefecture. Therefore, the generalizability of the findings may be limited.
Conclusion
This study found that in the Yamagata cohort, those living with someone in need of care had a higher risk of depression than those who did not, and those in this group were more likely than those at lower risk of depression to report economic hardship and low perceived sleep satisfaction, and to have difficulty with their daily activities.
Disclosure statement
The authors declare no conflicts of interest.
Authors' contributions
CU and KS conceived and designed the study, and drafted the manuscript. CU and KS analyzed the data. CU, KS, HI, YI, YM, and TK contributed substantially to the drafting of the manuscript. TK reviewed and wrote the manuscript. All the authors have read and approved the final version of the manuscript.
Ethics approval statement
This study was approved by the Ethics Review Committee of Yamagata University School of Medicine (2022‐99).
Patient consent statement
Written informed consent was obtained from all participants in the Yamagata Cohort Study.
Acknowledgements
This study was funded by the Global COE Program “Establishment of an International Research and Education Network for Molecular Epidemiology.” This study was supported in part by the Japan Society for the Promotion of Science KAKENHI Grant Number JP24‐K14108 awarded to Kaori Sakurada.
Uno C, Sakurada K, Inaba H, Ishida Y, Matsuda Y, Konta T. The relationship between lifestyle and the risk of depression among people living with someone who needs care: The Yamagata Cohort Study. Geriatr. Gerontol. Int. 2025;25:1503–1510. 10.1111/ggi.70184
Data availability statement
Data can be provided upon reasonable request.
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Associated Data
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Data Availability Statement
Data can be provided upon reasonable request.