DESK REVIEWS | 06.02.05. What is the average age of onset?
DESK REVIEW | 06.02.05. What is the average age of onset?
The age of onset of dementia has been studied in dementia cohorts and evaluated in hospital-based studies. In India, the proportion of patients with early-onset dementia is higher (49.9%) in comparison to developed countries (7-30%) (Das, Ghosal and Pal, 2012; Alladi et al., 2011). A study examining subtypes of dementia from a memory clinic in South India reported the mean age of onset of dementia as 66.3 years (Alladi et al., 2011). This is likely to be reflective of the demographic and epidemiologic profile of India. For example, lower levels of education and socioeconomic status, contribute to a higher number of individuals with vascular dementia (who are typically younger than persons with AD patient) (Alladi et al, 2011). Furthermore, lower referral rates of older elderly to hospitals as a result of lack of awareness and ‘sociocultural’ protection of elderly with memory loss in developing countries may also be contributing towards the lower age of onset reported by clinic studies (Alladi et al., 2011).
Alladi, S., Mekala, S., Chadalawada, S. K., Jala, S., Mridula, R., & Kaul, S. (2011). Subtypes of \Dementia: A Study from a Memory Clinic in India. Dementia and Geriatric Cognitive Disorders, 32(1), 32–38. https://doi.org/10.1159/000329862
Das, S., Ghosal, M., & Pal, S. (2012). Dementia: Indian scenario. Neurology India, 60(6), 618. https://doi.org/10.4103/0028-3886.105197
It is difficult to indicate when dementia begins because the onset is gradual. However, Young Onset Dementia (YOD) typically occurs before the age of 65 (Alzheimer’s Disease International (ADI) and World Health Organization (WHO), 2012). There is no information on the average age onset in Kenya.
Alzheimer’s Disease International (ADI) and World Health Organization (WHO). (2012). Dementia: A public health priority. United Kingdom. https://www.alzint.org/u/2020/08/Dementia-A-Public-Health-Priority.pdf