Attention Deficit/Hyperactivity Disorder and Risk of Dementia: A Systematic Review and Meta-Analysis.
Level 3 - non-randomized controlled study
Systematic review of observational cohort and case-control studies
PubMed 42352655 · doi:10.3390/brainsci16060646
What was done
Authors systematically searched PubMed, Embase, and Scopus for cohort and case-control studies examining the relationship between a prior diagnosis of attention deficit/hyperactivity disorder (ADHD) and the subsequent risk of dementia. Study quality was evaluated using the Newcastle-Ottawa scale, and pooled hazard ratios (HRs) were calculated for all-cause and subtype-specific dementia where data permitted.
What was found
Five studies met inclusion criteria: four cohort studies comprising 3,703,877 participants and one case-control study with 400 participants. The pooled HR for all-cause dementia was 2.52 (95% CI 1.51–4.22, p < 0.001), indicating a statistically significant higher risk among individuals with ADHD. Due to an insufficient number of available studies, meta-analyses could not be performed for Alzheimer's disease, vascular dementia, or Lewy body dementia.
Why it matters
These findings suggest that ADHD in adults is associated with a more than twofold increase in the hazard of developing dementia, highlighting the need to investigate shared mechanisms and long-term cognitive monitoring in this population.
Limits
The total number of eligible studies was very small (five overall, with all-cause meta-analysis relying on only four cohorts). Subtype-specific dementia risks could not be quantitatively synthesized, and the observational designs cannot rule out residual confounding, diagnostic biases, or establish a causal relationship.
Cited by
- supports Published scientific research demonstrates a relationship between ADHD and an increased risk of cognitive decline.