A longitudinal study of the impact of social network size and loneliness on cognitive performance in depressed older adults.

Objectives: To examine the association of social network size and loneliness with cognitive performance and -decline in depressed older adults.Method: A sample of 378 older adults [70.7 (7.4) years] with a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition diagnosis of current depressive disorder were recruited from primary care and specialized mental health care. Cognitive performance was assessed at baseline and 2 years follow-up with the Stroop colored-word test, a modified version of the Auditory Verbal Learning Task and the Digit Span subtest from the Wechsler Adult Intelligence Scale, encompassing four cognitive domains; processing speed, interference control, memory, and working memory. Social network size was assessed with the Close Person Inventory and loneliness with the de Jong Gierveld Loneliness Scale at baseline.Results: After adjusting for baseline working memory performance, loneliness was associated with impaired working memory after 2 years [B = -0.08 (-0.17 to 0.00)]. This association was no longer significant after adjusting for age, sex, education level, physical activity, alcohol use and depressive symptom severity [B = -0.07 (-0.16 to 0.03)]. A backward elimination procedure revealed education level to be the only covariable to explain this association. Loneliness was not associated with impairments or decline in other cognitive domains. Social network size was not associated with cognitive impairments or decline.Conclusion: Social network size and loneliness do not predict cognitive decline in depressed older adults.

Comparison of cognitive functioning as measured by the Ruff Figural Fluency Test and the CogState computerized battery within the LifeLines Cohort Study.

BACKGROUND: The Ruff Figural Fluency Test (RFFT; a pencil and paper test) and the CogState (a computerized cognitive test battery) are well-validated and suitable tests to evaluate cognitive functioning in large observational studies at the population level. The LifeLines Cohort Study includes the RFFT as baseline measurement and incorporated the CogState as replacement for the RFFT at follow-up. It is unknown how these two tests relate to each other. Therefore, the aim of this study is to examine the correlation between the RFFT and the CogState and the impact of demographic characteristics on this association. METHODS: A subcohort of the LifeLines Cohort Study, a large population based cohort study, participated in this study. Correlations between the RFFT and six subtasks of the CogState were examined. Subgroup analyses were performed to investigate the influence of age, education, and gender on the results. With sensitivity analyses we investigated the influence of computer experience and (physical) impairments. RESULTS: A total of 509 participants (mean age (SD): 53 years (14.6); range 18-87 years) participated in this study. All correlations between the RFFT and the CogState were statistically significant (except for the correlation between the RFFT error ratio and the CogState One Back Task), ranging from -0.39 to 0.28. Stratifying the analyses for age, education, and gender did not substantially affect our conclusions. Sensitivity analyses showed no substantial influence of level of computer experience or (physical) impairments. CONCLUSIONS: Correlations found in the present study were only weak to moderate, indicating that cognitive functioning measured by the RFFT does not measure the same components of cognitive functioning as six subtasks of the CogState. Computerized testing such as the CogState may be very well suited for large cohort studies to assess cognitive functioning in the general population and to identify cognitive changes as early as possible, as it is a less time- and labor intensive tool.

The relationship between social functioning and subjective memory complaints in older persons: a population-based longitudinal cohort study.

OBJECTIVE: Poor social functioning is associated with cognitive decline in older adults. It is unclear whether social functioning is also associated with subjective memory complaints (SMC). We investigated the association between social functioning and incident SMC and SMC recovery. METHODS: A population-based sample of 8762 older adults (aged ≥65 years) with good objective cognitive functioning at baseline (MMSE ≥26) from the LifeLines Cohort Study were followed for 1.5 years. Self-reported SMC were measured at baseline and after 1.5 years follow-up. Aspects of social functioning included marital status, household composition, social network size, social activity, quality of social relationships, social support, affection, behavioral confirmation, and status. RESULTS: Thirteen percent (513/3963) developed SMC during follow-up (incident SMC). Multivariate logistic regression analyses (adjusted for age, gender, education level, physical activity, alcohol use, smoking status, depression, arrhythmia, myocardial infarction, heart failure, stroke) showed that participants with better feelings of affection, behavioral confirmation and stable good social support had a lower risk of incident SMC. Thirty-four percent (1632/4799) reported recovery. Participants with good social functioning at baseline on all determinants reported more SMC recovery. People who remained stable in a relationship, stable in good quality of social relationships or increased in quality of social relationships more often report SMC recovery. CONCLUSIONS: Good social functioning is associated with less incident SMC and more SMC recovery over a follow-up period of 1.5 years. Albeit future confirmative studies are needed, we argue for targeting also social functioning when designing multidomain interventions to prevent or slow down cognitive decline. Copyright © 2016 John Wiley & Sons, Ltd.

Social relationships and cognitive decline: a systematic review and meta-analysis of longitudinal cohort studies.

BACKGROUND: Although poor social relationships are assumed to contribute to cognitive decline, meta-analytic approaches have not been applied. Individual study results are mixed and difficult to interpret due to heterogeneity in measures of social relationships. We conducted a systematic review and meta-analysis to investigate the relation between poor social relationships and cognitive decline. METHODS: MEDLINE, Embase and PsycINFO were searched for longitudinal cohort studies examining various aspects of social relationships and cognitive decline in the general population. Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using random effects meta-analysis. Sources of heterogeneity were explored and likelihood of publication bias was assessed. We stratified analyses according to three aspects of social relationships: structural, functional and a combination of these. RESULTS: We identified 43 articles. Poor social relationships predicted cognitive decline; for structural (19 studies): pooled OR: 1.08 (95% CI: 1.05-1.11); functional (8 studies): pooled OR: 1.15 (95% CI: 1.00-1.32); and combined measures (7 studies): pooled OR: 1.12 (95% CI: 1.01-1.24). Meta-regression and subgroup analyses showed that the heterogeneity could be explained by the type of social relationship measurement and methodological quality of included studies. CONCLUSIONS: Despite heterogeneity in study design and measures, our meta-analyses show that multiple aspects of social relationships are associated with cognitive decline. As evidence for publication bias was found, the association might be overestimated and should therefore be interpreted with caution. Future studies are needed to better define the mechanisms underlying these associations. Potential causality of this prognostic association should be examined in future randomized controlled studies.

Social relationships and risk of dementia: A systematic review and meta-analysis of longitudinal cohort studies.

It is unclear to what extent poor social relationships are related to the development of dementia. A comprehensive systematic literature search identified 19 longitudinal cohort studies investigating the association between various social relationship factors and incident dementia in the general population. Relative risks (RRs) with 95% confidence intervals (CIs) were pooled using random-effects meta-analysis. Low social participation (RR: 1.41 (95% CI: 1.13-1.75)), less frequent social contact (RR: 1.57 (95% CI: 1.32-1.85)), and more loneliness (RR: 1.58 (95% CI: 1.19-2.09)) were statistically significant associated with incident dementia. The results of the association between social network size and dementia were inconsistent. No statistically significant association was found for low satisfaction with social network and the onset of dementia (RR: 1.25 (95% CI: 0.96-1.62). We conclude that social relationship factors that represent a lack of social interaction are associated with incident dementia. The strength of the associations between poor social interaction and incident dementia is comparable with other well-established risk factors for dementia, including low education attainment, physical inactivity, and late-life depression.