Mental health symptoms and verbal fluency in elderly people: Evidence from the Spanish longitudinal study of aging

Clustering and switching analysis of verb fluency in individuals with Alzheimer's disease

PURPOSE

To investigate verb fluency performance in individuals with Alzheimer's disease compared with healthy older adults by analyzing total correct responses, number of clusters, average cluster size, and number of switches.

METHODS

This is a case-control study of 39 healthy older adults and 29 older adults with a diagnosis of Alzheimer's disease. Verb fluency performance was analyzed in terms of total number of correct verbs retrieved, number of clusters, average cluster size, and number of switches. To obtain the study outcomes, we previously conducted a procedure for categorization of the verbs that would compose the clusters. The classification of verbs was adapted for this study, including assessment by raters and analysis of inter-rater reliability.

RESULTS

Individuals with Alzheimer's disease showed significantly poorer performance than healthy controls in the number of switches and total number of correct verbs retrieved. The two groups did not differ significantly in the other measures.

CONCLUSION

In this study, individuals with Alzheimer's disease showed impaired verb fluency, characterized by a reduced number of verbs retrieved and fewer transitions between verb categories. The findings suggest that, in Alzheimer's disease, verb fluency is more sensitive to cognitive deficits resulting from executive dysfunction than from semantic disruption.

Loneliness and Cognitive Function in Older Adults Without Dementia: A Systematic Review and Meta-Analysis

BACKGROUND

Loneliness has been highlighted as a risk factor for dementia. However, the nature of the relationship between loneliness and cognitive function prior to onset of dementia is unclear.

OBJECTIVE

The aim of this systematic review and meta-analysis was to examine the relationship between loneliness and cognitive function in samples screened for dementia at study commencement.

METHODS

Five electronic databases (PubMed, PsycNET, Web of Science, EBSCOhost, Scopus) were searched from inception to August 31, 2021. A narrative review and random-effects meta-analysis were conducted on studies meeting search criteria. PROSPERO registration number: CRD42020155539.

RESULTS

The sixteen studies that met inclusion criteria involved 30,267 individuals, with mean age ranging from 63.0 to 84.9 years. Studies varied in dementia screening criteria, measurement of loneliness and cognitive function, and statistical modeling approach. The narrative review indicated that loneliness was associated with poorer global cognition, episodic memory, working memory, visuospatial function, processing speed, and semantic verbal fluency. Results of the meta-analysis indicated that loneliness was negatively associated with global cognitive function (overall r = -0.08; 95% CI = -0.14, -0.02; n = 6). Due to lack of sufficient data and heterogeneity between studies, we were unable to explore associations with other cognitive domains or longitudinal associations.

CONCLUSION

Loneliness is associated with subtle impairment across multiple cognitive domains in older adults who were screened for dementia. Better characterization of this relationship will provide important information about how loneliness contributes to the clinical and pathological sequalae of AD and be informative for risk reduction and early detection strategies.

The prevalence of loneliness across 113 countries: systematic review and meta-analysis

OBJECTIVES

To identify data availability, gaps, and patterns for population level prevalence of loneliness globally, to summarise prevalence estimates within World Health Organization regions when feasible through meta-analysis, and to examine temporal trends of loneliness in countries where data exist.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Embase, Medline, PsycINFO, and Scopus for peer reviewed literature, and Google Scholar and Open Grey for grey literature, supplemented by backward reference searching (to 1 September 2021) ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Observational studies based on nationally representative samples (n≥292), validated instruments, and prevalence data for 2000-19. Two researchers independently extracted data and assessed the risk of bias using the Joanna Briggs Institute checklist. Random effects meta-analysis was conducted in the subset of studies with relatively homogeneous research methods by measurement instrument, age group, and WHO region.

RESULTS

Prevalence data were available for 113 countries or territories, according to official WHO nomenclature for regions, from 57 studies. Data were available for adolescents (12-17 years) in 77 countries or territories, young adults (18-29 years) in 30 countries, middle aged adults (30-59 years) in 32 countries, and older adults (≥60 years) in 40 countries. Data for all age groups except adolescents were lacking outside of Europe. Overall, 212 estimates for 106 countries from 24 studies were included in meta-analyses. The pooled prevalence of loneliness for adolescents ranged from 9.2% (95% confidence interval 6.8% to 12.4%) in South-East Asia to 14.4% (12.2% to 17.1%) in the Eastern Mediterranean region. For adults, meta-analysis was conducted for the European region only, and a consistent geographical pattern was shown for all adult age groups. The lowest prevalence of loneliness was consistently observed in northern European countries (2.9%, 1.8% to 4.5% for young adults; 2.7%, 2.4% to 3.0% for middle aged adults; and 5.2%, 4.2% to 6.5% for older adults) and the highest in eastern European countries (7.5%, 5.9% to 9.4% for young adults; 9.6%, 7.7% to 12.0% for middle aged adults; and 21.3%, 18.7% to 24.2% for older adults).

CONCLUSION

Problematic levels of loneliness are experienced by a substantial proportion of the population in many countries. The substantial difference in data coverage between high income countries (particularly Europe) and low and middle income countries raised an important equity issue. Evidence on the temporal trends of loneliness is insufficient. The findings of this meta-analysis are limited by data scarcity and methodological heterogeneity. Loneliness should be incorporated into general health surveillance with broader geographical and age coverage, using standardised and validated measurement tools.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019131448.

Comparison of verbal fluency in monolingual and bilingual elderly in Iran

Verbal fluency is one of the first and most important cognitive functions that deteriorate during the aging process. Verbal fluency is defined as the skill and speed of finding words and finding semantic and phonetic connections between words. One of the most important factors in verbal fluency is bilingualism. Therefore, the current study aimed to investigate the effect of bilingualism on the verbal fluency of the elderly in Iran. A total of 12 normal elderly bilingual (Arabic-Persian) speakers and 12 normal elderly monolingual (Persian) speakers participated in this comparative-analytical study. To assess verbal fluency, two semantic and phonetic fluency tasks were used. Data were analyzed using the Wilcoxon-Mann-Whitney tests. The results obtained from the comparison of phonetic fluency and semantic fluency of native languages of the two groups showed a better performance of monolingual participants in semantic fluency and phonetic fluency tasks in Persian language compared to the Arabic bilingual elderly. No difference was observed in verbal fluency of Persian monolinguals and bilinguals. However, in bilingual elderly participants, faster retrieval was observed in Persian language than in Arabic. This can be considered in assessment and treatment measures for Arabic-Persian bilinguals.