Association of life-course depression with the risk of dementia in late life: A nationwide twin study

Wenzhe Yang, Xuerui Li, Kuan-Yu Pan, Rongrong Yang, Ruixue Song, Xiuying Qi, Nancy L Pedersen, Weili Xu

Research output: Contribution to JournalArticleAcademicpeer-review

10 Citations (Scopus)


INTRODUCTION: Whether depression is a prodromal phase or risk factor for dementia is under debate. We aimed to unveil the nature of depression-dementia association by looking into the time window of depression occurrence.

METHODS: Dementia-free twins (n = 41,727) from the Swedish Twin Registry were followed-up for 18 years. Data were analyzed using generalized estimating equation (GEE) for all individuals and conditional logistic regression for co-twin matched pairs.

RESULTS: In the GEE model, multi-adjusted odds ratios (ORs; 95% confidence intervals [CIs]) of dementia were 1.46 (1.09-1.95) for mid-life, 2.16 (1.82-2.56) for late-life, 2.24 (1.49-3.36) for mid- to late-life, and 2.65 (1.17-5.98) for lifelong depression. The ORs in conditional logistic regression and in GEE did not differ significantly (P = 0.60). Education ≥8 years attenuated dementia risk associated with mid-life depression.

DISCUSSION: Not only late-life depression, but also mid-life depression is associated with dementia. Genetic and early-life environmental factors could not account for this association. Education ≥8 years might buffer the impact of mid-life depression on dementia.

Original languageEnglish
Pages (from-to)1383-1390
Number of pages8
JournalAlzheimer's & dementia : the journal of the Alzheimer's Association
Issue number8
Early online date2021
Publication statusPublished - Aug 2021


  • dementia
  • depression
  • education
  • population-based twin study
  • the Swedish twins

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