|Year : 2022 | Volume
| Issue : 3 | Page : 276-281
Loneliness, social isolation, traumatic life events, and risk of alzheimer's dementia: A case–Control study
Insha Rauf1, Arshad Hussain1, Fazle Roub2
1 Department of Psychiatry, Institute of Mental Health and Neuroscience, Government Medical College, Srinagar, Jammu and Kashmir, India
2 Department of Psychiatry, Drug De-Addiction and Treatment Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India
|Date of Submission||18-Nov-2020|
|Date of Decision||22-May-2021|
|Date of Acceptance||06-Jul-2021|
|Date of Web Publication||23-Sep-2022|
Dr. Insha Rauf
Department of Psychiatry, Institute of Mental Health and Neuroscience, Government Medical College, Srinagar - 190 003, Jammu and Kashmir
Source of Support: None, Conflict of Interest: None
Context: Alzheimer's disease, an affliction of old age, is the leading cause of dementia worldwide. Vascular risk factors such as hypertension, dyslipidemia, hyperinsulinemia, type II diabetes, and obesity have been widely implicated in the pathogenesis of dementia. Environmental factors such as social isolation, loneliness, and traumatic life events, though less studied, have been associated with an increased risk of developing Alzheimer's disease. Aim: We aimed to find out if loneliness, social isolation, and traumatic life events are risk factors for Alzheimer's dementia (AD). Materials and Methods: This was a case–control study based on 100 patients selected for the study using Mini-Mental State Examination (MMSE) (Kashmiri version) and diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria for dementia of the Alzheimer's type. Patients having “mild degree of impairment” on MMSE (Kashmiri version) were taken up for the study. Patients were assessed using De Jong Gierveld Loneliness Scale (eleven items), Lubben Social Network Scale, and Traumatic Life Events Checklist. Results: Loneliness is associated with an increased risk of developing AD. Social isolation acts as a proxy indicator of loneliness. The number of traumatic events is not associated with an increased risk of developing AD. However, death of a child was associated with an increased risk of developing AD (P = 0.033). Conclusion: Loneliness is a robust risk factor for dementia and as such more research needs to focus on it so that suitable cognitive behavioral interventions may be developed and refined to help the vulnerable population.
Keywords: Dementia, isolation, loneliness, trauma
|How to cite this article:|
Rauf I, Hussain A, Roub F. Loneliness, social isolation, traumatic life events, and risk of alzheimer's dementia: A case–Control study. Indian J Soc Psychiatry 2022;38:276-81
|How to cite this URL:|
Rauf I, Hussain A, Roub F. Loneliness, social isolation, traumatic life events, and risk of alzheimer's dementia: A case–Control study. Indian J Soc Psychiatry [serial online] 2022 [cited 2022 Oct 3];38:276-81. Available from: https://www.indjsp.org/text.asp?2022/38/3/276/356783
| Introduction|| |
Alzheimer's disease, the leading cause of dementia, affects about 10% of those aged above 65 years and about 30% of people aged above 80 years. The World Health Organization projections suggest that by 2025, there will be about 900 million people aged above 60 years in the developing countries. By 2040, if growth in the older population continues with no preventive measures for dementia in place, 71% of the global burden (81 million cases) of dementia will be in the developing world. It is, therefore, imperative for researchers to focus on potentially modifiable risk factors of dementia. A lot of research effort has gone into elucidation of modifiable biological risk factors of Alzheimer's dementia (AD) such as hypertension, diabetes, and dyslipidemia.,,, Very less research has been conducted on the modifiable psychosocial risk factors. We attempted to study three potentially modifiable risk factors of AD, namely social isolation, loneliness, and traumatic life events using a case–control design. In addition, there has been no research on modifiable psychosocial risk factors of AD from Asia and it was in this context that the present study was conducted.
Various hypotheses have been put forward about how loneliness, social isolation, and traumatic life events contribute to the risk of developing AD. Holwerda et al. hypothesized that feelings of loneliness may actually be caused by the process of dementia itself, whereby increasing neuronal loss leads to personality changes and a deterioration of social skills with resultant feelings of loneliness. However, this so-called reversed causation has been ruled out by several studies., Wilson et al. suggested that loneliness adds to the deleterious effects of age-related neuropathology, possibly, by compromising neural systems underlying cognition and memory (i.e., decreasing neural reserve). Ellwardt et al. (2013) also suggested that loneliness mediates the relation between cognitive decline and social isolation. Charles et al. suggested that traumatic life events cause increased activation of the hypothalamic–pituitary–adrenal axis with resultant increased cortisol. Elevated glucocorticoid levels have been found to enhance Aβ production by increasing amyloid precursor protein (APP) levels and increased activity of β-APP-cleaving enzyme, thereby highlighting important role of cortisol in the pathogenesis of AD.
| Materials and Methods|| |
This study was conducted at the memory clinic of a tertiary care hospital in Kashmir, India, and research work was initiated following approval by the Institutional Ethical Committee and Board of Research Studies of the institute. It was a case–control study which was conducted over a period of 2 years (2018–2019).
The study included patients with mild dementia because the study involved recall of past events which is not affected in such patients. Patients who did not consent were not included in the study. Those with comorbid major depression at presentation or psychotic features along with dementia were not included in the study. The reasons of such exclusion were that a current diagnosis of depression would have led to a biased recall of events whereas patients having psychotic features along with dementia would not have been able to sit in face-to-face interviews. Patients with lifetime diagnosis of depression were not included because depression itself has been shown to be a risk factor for dementia.
All patients attending and referred to (from the Department of Neurology of our institute and two private clinics: one of psychiatrist and one of neurologist) the memory clinic of the hospital were screened using Mini-Mental State Examination (MMSE, Kashmiri version). The MMSE (Kashmiri version) is a validated and standardized tool for the Kashmiri population. All the patients scoring 18–23 (mild degree of impairment) on MMSE (Kashmiri version) and fulfilling the inclusion and exclusion criteria (n = 134) were further evaluated and the diagnosis of AD where applicable was made as per the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria for dementia of the Alzheimer's type (n = 100). The diagnosis was confirmed by a consultant psychiatrist. All patients whose diagnosis was confirmed were taken up for the study (n = 100).
Fifty-three age-matched controls were identified in door-to-door visits done by a psychiatrist with the help of Anganwadi workers in the community. On detailed assessment, three of these were excluded as one had clinical dementia and two were currently depressed. None of those identified refused to participate in the study.
Demographic characters which included details of name, age, occupation, marital status, educational attainment, and socioeconomic status were noted for cases as well as controls. In addition, information about vascular risk factors (dyslipidemia, hypertension, type II diabetes mellitus, cerebrovascular disease, and cardiovascular disease) was also noted. This was done to address the issue of potential confounders and to adjust the final results for confounders. Patients were assessed using De Jong Gierveld Loneliness Scale (DJG Loneliness Scale), Lubben Social Network Scale (LSNS), and Life Events Checklist (LEC). All three scales are validated and reliable.,,
The DJG Scale is an eleven-item scale. On measures of homogeneity, it consists of two subscales, the positive and negative subscales. The negative subscale measures what Weiss calls “emotional loneliness” and the positive subscale measures what he called “social loneliness.” Emotional loneliness refers to the subjective response (restless depression, unfocussed dissatisfaction, anxiety and apprehension) of a person to the absence of a generalized attachment figure (rather than a particular person) or pining for a certain kind of relationship (objectless pining) while as social loneliness (boredom and feelings of exclusion) results from loss of contact with those who share ones concern. Both social loneliness and emotional loneliness are subjective experiences and all the eleven items on this scale measure a highly subjective phenomenon, i.e., loneliness.
The LSNS is a ten-item scale to assess family (items 1, 2, and 3), friend (items 4, 5, and 6), and confidant networks (items 7 and 8). In addition, item 9 has two parts to assess helping others and the last item (item 10) assesses living arrangements. The LSNS was used to measure social isolation. Items 1, 2, 6, and 10 of the LSNS measure the number of people in a person's social network or the social network size of a person and the frequency of interaction, in other words the quantitative aspect of his social circle. The rest of the items (items 3, 4, 5, 7, 8, and 9) aim to elicit the nature or quality of those relationships by measuring the depth of that relation in terms of exchanges such as sharing of problems and concerns, decision-making, and sharing of daily chores or simply the amount of instrumental and emotional support exchanges.
The LEC is a 17-item scale which lists a number of difficult or stressful things which happen to people. It also lists whether the individual has ever experienced or witnessed any stressful event or heard about the event. However, we included only those traumatic events which had happened to the study subjects. These scales were used in face-to-face interviews and were administered in the middle of the interview when considerable degree of self-disclosure from the respondent might be expected. Care was taken to explain the questions in the native language of the patient where needed. The participants were asked to consider their entire life and make an overall assessment of how they felt and accordingly answer the questions on the scales. Details were corroborated by family members wherever possible.
Categorical variables were summarized as frequency and percentage. The scores on DJGS, LSNS, and number of traumatic life events were summarized as mean and standard deviation. Items 1, 2, 6, and 10 of the LSNS were separately scored as these are a measure of social network size (number and frequency of association) and have been associated with dementia. Items 3, 4, 5, 7, 8, and 9 of the LSNS were also separately scored as a measure of instrumental and emotional support exchanges as they have also been associated with both increased and decreased risks of dementia., Both were summarized as mean and standard deviation.
Mean difference in scores between cases and controls was reported as “mean score in cases − mean score in controls” with 95% confidence interval. Independent samples t-test was used to analyze the difference in mean scores between cases and controls. To measure the effect of scores on case status (mild dementia) adjusted for marital status and socioeconomic status, multivariable logistic regression analysis was done. For marital status, “widowed” was chosen as the reference category, and for socioeconomic status, “upper middle” was chosen as the reference category. P < 0.05 was taken as statistically significant. Analysis was done using SPSS version 23.0 (IBM Corp., Armonk, NY, USA).
| Results|| |
Characteristics of study population
There was no statistically significant difference between cases and controls on measures of age, sex, educational attainment, family type, medical disorders, and smoking status [Table 1]. Therefore, these potential confounders were not required to be adjusted in the final analysis.
The difference in socioeconomic status among cases and controls was significant with cases belonging to higher socioeconomic status (P < 0.001). The difference in marital status between the two groups was significant (P < 0.01), with cases being more likely to be married [Table 1].
Loneliness, social isolation, and traumatic life events
Loneliness was associated with an increased risk of developing AD (P < 0.01). Scores on the De Jong Gierveld Loneliness Scale revealed that 63% of cases and 32% of controls were lonely. Social isolation was associated with an increased risk of developing AD (P = 0.03). Scores on the LSNS indicate that 33% of cases and 26% of controls were at moderate risk of social isolation and 21% of cases and 14% of controls were at high risk of social isolation (data not shown).
Social network size (the number of people in a person's social network and the frequency of interaction) as measured by scores from items 1, 2, 6, and 10 of the LSNS was not associated with an increased risk of developing AD [Table 2]. The instrumental and emotional support exchanges as measured by items 3, 4, 5, 7, 8, and 9 were also not associated with an increased risk of developing AD [Table 2].
|Table 2: Comparison of loneliness, social isolation, network size, emotional and instrumental support exchanges, and traumatic life events|
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The mean number of traumatic events in cases was 2.28, while in controls, it was 2.17. The difference in the mean number of traumatic events between cases and controls was not statistically significant (P = 0.63) [Table 2]. A specific traumatic life event, i.e., death of a child, was associated with an increased risk of developing dementia. Twenty-two percent of cases reported death of a child against 8% of controls and it was statistically significant (P = 0.03). Overall, 96% of cases and 91% of controls reported at least one traumatic life event (data not shown).
On multivariable regression analysis, when we controlled for social isolation, there was no statistically significant association between loneliness and AD [Table 3]. However, when we controlled for social network size alone, the association between loneliness and AD remained significant (P = 0.01).
|Table 3: Multivariable regression analysis (adjusted for social network size alone)|
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| Discussion|| |
Socioeconomic status was assessed using education, profession, and family income. The difference between education among cases and controls was not significant. The difference in socioeconomic status was found to be due to higher income among the cases. This difference could be due to the fact that higher-income people were more likely to be socio-occupationally functional and hence subtle changes in cognition and function are very noticeable, coupled with the fact that awareness about dementia is limited to the affluent class of our society and also the fact that “forgetting” is considered normal among less affluent class of our society. Hence, only affluent people might have sought medical attention for the presenting symptoms of mild dementia.
The controls in contrast were identified in community surveys and hence may be more representative of the community in general. In addition, a majority of research links higher socioeconomic status to lesser risk of dementia owing to healthier lifestyle associated with higher socioeconomic status.
Being married was associated with an increased risk of loneliness. Being married has been linked with a decreased risk of loneliness, however, there are studies which link being married to a higher risk of social isolation and hence loneliness. This maybe particularly relevant to our study population and culture where marriages are arranged and friends rather than spouse would be chosen as confidants and support systems. Another reason could be that negative experiences in marriage were more in the cases and hence the loneliness. Although we did not explore this area in our study, it has been previously explored in some studies.
In addition, on regression analysis, the difference in marital status between cases and controls was not statistically significant, suggesting that the difference in marital status may be linked to difference in socioeconomic status.
The prevalence of loneliness in controls was comparable to that found by de Jong Gierveld in a study conducted in The Netherlands, where they reported that 32% of the elderly population was lonely. The equal prevalence of loneliness in The Netherlands (a developed country) and Kashmir (part of a developing nation) suggests that loneliness in individuals maybe a heritable trait rather than an effect of the social environment. This further highlights the need for more research on this topic as individuals vulnerable to loneliness could then be identified and suitable interventions in the form of cognitive behavioral therapy or other therapies be instituted. This could serve as primary prevention against AD. Further, the scores also indicate that loneliness is associated with an increased risk of developing AD. These findings are in agreement with previous studies suggesting an association between loneliness and risk of developing AD; both emotional loneliness and social loneliness were associated with an increased risk of developing AD. This is in agreement with previous studies which link loneliness with an increased risk of developing AD.,,
Social isolation was associated with an increased risk of developing AD; further, the scores on LSNS showed a strong negative correlation with the scores on the positive subscale of the De Jong Gierveld Loneliness Scale which implies that as the social isolation increased, so did the social loneliness. This may suggest that the link between social isolation and dementia is mediated through social loneliness. This is also supported by results on multivariable regression analysis where loneliness is no longer associated with an increased risk of developing dementia after we control for social isolation. This is in agreement with previous studies which link social isolation with an increased risk of developing AD.
The lack of association between social network size and AD is in agreement with a previous study. However, there is another study linking decreasing network size to increased risk of dementia.
The instrumental and emotional exchanges of support were also not linked to an increased risk of dementia. This is in contrast to most of the studies where emotional support exchanges have been linked to a decreased risk of AD. This finding in our study maybe due to the small sample size.
Our results also indicate that the mean number of traumatic life events is not related to the development of dementia. However, specific life events such as death of a child are related to the development of AD. A detailed search on Google Scholar using the keywords “dementia,” “trauma,” and “life traumatisms” yielded only one study that has reported death of a child to be associated with an increased risk of developing AD. There are studies linking other life traumatisms to the development of AD such as severe illness in a child, death of a parent in childhood, death of a close relative, and death of a friend.,, There are also studies linking AD to prolonged stress-, loss-, and depression-inducing events. It may, therefore, be suggested that a traumatic event of sufficient severity rather than many traumatic events of subthreshold intensity are associated with the development of AD. This could also mean that loss of a child results in loss of an important relation which would have otherwise helped in preventing loneliness, so that certain traumatic events could be thought of as mediating the relationship between loneliness and dementia.
A strength of the present study is that the diagnosis of dementia was made using reliable diagnostic and classification systems and was confirmed by a senior psychiatrist. The interviews with study subjects were performed by a trained psychiatrist. All study subjects were interviewed by the same interviewer eliminating any bias arising due to interindividual assessment. In addition, we assessed loneliness, social isolation, and traumatic life events with elaborate scales with each interview lasting 60–80 min (allowing sufficient time to establish rapport between study subjects and interviewer).
Our study has certain limitations that need to be mentioned. The sample size was small. Since our study was a retrospective study, it was subject to recall bias even though it was minimized to a certain extent by corroborating the details by family members. In addition, since loneliness has also been conceptualized as an effect rather than a cause of dementia, the patients' current state of loneliness may have led to a biased recall of past events. In assessing patients for traumatic life events, we did not ask whether such events were perceived as stressful, as interindividual coping ability is significantly different and therefore the stress generated by life events may be different for different individuals.
| Conclusion|| |
To conclude, loneliness, social isolation, and specific but not the mean number of traumatic life events are associated with an increased risk of developing AD. These findings assume even more importance as several intervention studies have shown that stimulating friendships and increasing support in social networks are successful means to reduce loneliness and eventually improve older people's cognitive functioning.,,
We would like to thank Dr. Inam, Assistant professor, Department of Community Medicine, GMC, Srinagar, for his valuable inputs about statistical analysis.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]