Key points from article :
Vitamin D deficiency, depression and diabetes increase the risk of young-onset dementia, a major study suggests.
The study challenges the notion that genetics are the sole cause of the condition.
It looked at data from over 350,000 under-65s from across the UK.
Identified 15 risk factors, including alcohol abuse, stroke, social isolation and hearing impairment.
Those with a higher formal education were seen to be at less of a risk.
"This pioneering study shines important and much-needed light on factors that influence the risk of young-onset dementia," - David Llewellyn, Professor at University of Exeter.
Our research could "herald a new era" for interventions to reduce new cases, said Janice Ranson, one of the study's authors.
Study led by Maastricht University and University of Exeter Medical School, and was published in the Jama Neurology journal.
