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Bilingualism does not alter cognitive decline or dementia risk among Spanish-speaking immigrants
Zahodne LB, Schofield PW, Farrell MT, Stern Y, Manly JJ.. Neuropsychology, 2013-11-04
Topic: Risk, prevention and care in population studies
Objective Clinic-based studies suggest that dementia is diagnosed at older ages in bilinguals compared with monolinguals. The current study sought to test this hypothesis in a large, prospective, community-based study of initially nondemented Hispanic immigrants living in a Spanish-speaking enclave of northern Manhattan. Method Participants included 1,067 participants in the Washington/Hamilton Heights Inwood Columbia Aging Project (WHICAP) who were tested in Spanish and followed at 18-24 month intervals for up to 23 years. Spanish-English bilingualism was estimated via both self-report and an objective measure of English reading level. Multilevel models for change estimated the independent effects of bilingualism on cognitive decline in 4 domains: episodic memory, language, executive function, and speed. Over the course of the study, 282 participants developed dementia. Cox regression was used to estimate the independent effect of bilingualism on dementia conversion. Covariates included country of origin, gender, education, time spent in the United States, recruitment cohort, and age at enrollment. Results Independent of the covariates, bilingualism was associated with better memory and executive function at baseline. However, bilingualism was not independently associated with rates of cognitive decline or dementia conversion. Results were similar whether bilingualism was measured via self-report or an objective test of reading level. Conclusions This study does not support a protective effect of bilingualism on age-related cognitive decline or the development of dementia. In this sample of Hispanic immigrants, bilingualism is related to higher initial scores on cognitive tests and higher educational attainment and may not represent a unique source of cognitive reserve.
Key findings
- Objective Clinic-based studies suggest that dementia is diagnosed at older ages in bilinguals compared with monolinguals.
- Results Independent of the covariates, bilingualism was associated with better memory and executive function at baseline.
- However, bilingualism was not independently associated with rates of cognitive decline or dementia conversion.
- Results were similar whether bilingualism was measured via self-report or an objective test of reading level.
Why it matters
In 1,067 Spanish-speaking Hispanic immigrants in northern Manhattan, followed for up to 23 years, bilinguals scored higher on memory and executive function at the start. However, bilingualism was not independently linked to how fast thinking declined or to developing dementia (282 people did), whether it was measured by self-report or an English reading test. The authors conclude that bilingualism here tracks "higher educational attainment and may not represent a unique source of cognitive reserve". This is one community study, and other research has reported later diagnosis in bilinguals.
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Study details
- Participants1,067
- Evidence strengthModerate
How this study scored 54/100
Published in a peer-reviewed journal. Scored zero for study design, effect reported and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Neuropsychology) |
| Journal's citation record | 2 / 4 | Neuropsychology: journal h-index 183 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2014 — within 20 year(s) of the newest study here |
| Sample size | 3 / 4 | 1,067 participants |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 5 / 7 | Cited 236 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 16.9 citations a year over 14 year(s) since 2014 |
| Impact for its field and year | 4 / 6 | Cited 10.5× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 2 / 6 | Cited by 9 other studies in this library |
| Still being cited | 2 / 4 | Cited 29 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Jennifer J. Manly: h-index 101 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | Columbia University: institution h-index 1,824 (OpenAlex) |
| Multi-centre collaboration | 1 / 3 | OpenAlex lists 3 institution(s) in 3 countries |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 24188113) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 54 / 100 | — |
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Read the original
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Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.
APA 7th
Zahodne, L. B., Schofield, P. W., Farrell, M. T., Stern, Y., & Manly, J. J. (2014). Bilingualism does not alter cognitive decline or dementia risk among Spanish-speaking immigrants. Neuropsychology. https://doi.org/10.1037/neu0000014
Vancouver
Zahodne LB, Schofield PW, Farrell MT, Stern Y, Manly JJ. Bilingualism does not alter cognitive decline or dementia risk among Spanish-speaking immigrants. Neuropsychology. 2014. doi:10.1037/neu0000014. PMID: 24188113.
BibTeX
@article{zahodne2014-24188113,
author = {Zahodne, L. B. and Schofield, P. W. and Farrell, M. T. and Stern, Y. and Manly, J. J.},
title = {{Bilingualism does not alter cognitive decline or dementia risk among Spanish-speaking immigrants}},
journal = {Neuropsychology},
year = {2014},
doi = {10.1037/neu0000014},
pmid = {24188113},
url = {https://doi.org/10.1037/neu0000014}
}
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