Insulin resistance, age and depression's impact on cognition in middle-aged adults from the PREVENT cohort

BMJ Ment Health. 2023 May;26(1):e300665. doi: 10.1136/bmjment-2023-300665.


Background: Alzheimer's disease (AD), type 2 diabetes mellitus (characterised by insulin resistance) and depression are significant challenges facing public health. Research has demonstrated common comorbidities among these three conditions, typically focusing on two of them at a time.

Objective: The goal of this study, however, was to assess the inter-relationships between the three conditions, focusing on mid-life (defined as age 40-59) risk before the emergence of dementia caused by AD.

Methods: In the current study, we used cross-sectional data from 665 participants from the cohort study, PREVENT.

Findings: Using structural equation modelling, we showed that (1) insulin resistance predicts executive dysfunction in older but not younger adults in mid-life, that (2) insulin resistance predicts self-reported depression in both older and younger middle-aged adults and that (3) depression predicts deficits in visuospatial memory in older but not younger adults in mid-life.

Conclusions: Together, we demonstrate the inter-relations between three common non-communicable diseases in middle-aged adults.

Clinical implications: We emphasise the need for combined interventions and the use of resources to help adults in mid-life to modify risk factors for cognitive impairment, such as depression and diabetes.

Keywords: delirium & cognitive disorders; depression & mood disorders; psychiatry.

MeSH terms

  • Adult
  • Aged
  • Alzheimer Disease* / psychology
  • Cognition
  • Cohort Studies
  • Cross-Sectional Studies
  • Depression / epidemiology
  • Diabetes Mellitus, Type 2* / epidemiology
  • Humans
  • Insulin Resistance*
  • Middle Aged