Low childhood IQ linked to dementia risk later in life

A study by researchers in Scotland has discovered a link between childhood IQ and dementia.

The researchers from Edinburgh University compared the records of 173 people who took part in the Scottish Mental Survey of 1932, a mental ability test taken by almost every child aged 11 in Scotland, they found that lower childhood IQ increased the risk of vascular dementia.

This group was compared to one set of control participants of the same age and gender and for another group of controls, the researchers made sure that the cases and controls came from families where the fathers had similar types of occupations.

The researchers found the people with vascular dementia were 40 percent more likely to have low test scores when they were children than the people who did not develop dementia but this difference was not true for those with Alzheimer's disease.

Vascular dementia is the second most common form of dementia after Alzheimer's disease, and is usually linked to high blood pressure, high cholesterol and smoking and occurs when the blood flow to the brain is impaired.

Lead researcher Dr. Brian McGurn says their research was based on unique data, and suggests a possible link between mental ability in early life and the risk of developing vascular dementia.

Dr. McGurn says it means the link can be demonstrated independently of factors such as socio-economic status and education and suggests that introducing measures early in life to lower blood pressure and discourage smoking could help those with a lower IQ reduce the risk of developing the brain illness in later life.

The study 'Childhood cognitive ability and risk of late-onset Alzheimer and vascular dementia' was supported by the Alzheimer's Research Trust and a Royal Society Wolfson Research Merit Award and is published in the Neurology journal.