Prevalence of epilepsy among people with intellectual disabilities: A systematic review

Seizure. 2015 Jul:29:46-62. doi: 10.1016/j.seizure.2015.03.016. Epub 2015 Mar 30.


Purpose: Epilepsy is more common in people with intellectual disabilities than in the general population. However, reported prevalence rates vary widely between studies. This systematic review aimed to provide a summary of prevalence studies and estimates of prevalence based on meta-analyses.

Method: Studies were identified via electronic searches using Medline, Cinahl and PsycINFO and cross-citations. Information extracted from studies was tabulated. Prevalence rate estimates were pooled using random effects meta-analyses and subgroup analyses were conducted.

Results: A total of 48 studies were included in the tabulation and 46 studies were included in meta-analyses. In general samples of people with intellectual disabilities, the pooled estimate from 38 studies was 22.2% (95% CI 19.6-25.1). Prevalence increased with increasing level of intellectual disability. For samples of people with Down syndrome, the pooled estimate from data in 13 studies was 12.4% (95% CI 9.1-16.7), decreasing to 10.3% (95% CI 8.4-12.6) following removal of two studies focusing on older people. Prevalence increased with age in people with Down syndrome and was particularly prevalent in those with Alzheimer's/dementia.

Conclusion: Epilepsy is highly prevalent in people with intellectual disabilities. Services must be equipped with the skills and information needed to manage this condition.

Keywords: Down syndrome; Epilepsy; Intellectual disabilities; Prevalence.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Review
  • Systematic Review

MeSH terms

  • Epilepsy / epidemiology*
  • Humans
  • Intellectual Disability / epidemiology*
  • Prevalence