In a new study it has been found that adults who suffer from attention-deficit and hyperactivity disorder (ADHD) are more than three times more likely to develop a common form of degenerative dementia.
Researchers from Argentina confirmed the link during a study of 360 patients with degenerative dementia and 149 healthy controls, matched by age, sex and education. The dementia patients comprised 109 people with dementia with Lewy bodies (DLB) and 251 with Alzheimer's.
"Our study showed that 48 per cent of patients with DLB - the second most common cause of degenerative dementia in the elderly after Alzheimer's - had previously suffered from adult ADHD," said lead author Dr Angel Golimstok.
"This was more than three times the 15 per cent rate found in both the control group and the group with Alzheimer's.
"DLB is thought to account for around ten per cent of dementia cases in older people, but it tends to be under-diagnosed because it shares some characteristics with both Alzheimer's and Parkinson's.
"It is a degenerative neurological condition that has a progressive and disabling effect on a person's mental and physical skills. Other symptoms can include recurrent and realistic visual hallucinations, fluctuations in the person's everyday abilities and spontaneous movement problems similar to those observed in Parkinson's.
"ADHD is one of the most common behaviour disorders in child and adolescent psychiatry and the problems it causes, such as difficulty paying attention, hyperactivity and doing things impulsively, can continue into adulthood.
"It is believed that the same neurotransmitter pathway problems are involved in the development of both conditions, so our research set out to test the theory that adult ADHD often precedes DLB," Golimstok added
The study has been published in the European Journal of Neurology.