It's claimed taking over-the-counter hayfever or sleeping tablets could increase your risk of dementia.

Scientists in the US followed nearly 3,500 over-65s over several years. The study looks at over-the -counter medications like Benadryl, Nytol and Piriton.

They found those who took a regular dose of so-called 'anticholinergics' were 54% more likely to develop conditions like Alzheimer's.

Experts here are advising people to see their GP before stopping using the drugs, though.

Dr Doug Brown, from the UK's Alzheimer's Society told the BBC: "There have been concerns that regular use by older people of certain medications with anticholinergic effects, such as sleep aids and hay-fever treatments, can increase the risk of dementia in certain circumstances, which this study supports.

"However, it is still unclear whether this is the case and if so, whether the effects seen are a result of long-term use or several episodes of short-term use. More robust research is needed to understand what the potential dangers are, and if some drugs are more likely to have this effect than others.

"We would encourage doctors and pharmacists to be aware of this potential link and would advise anyone concerned about this to speak to their GP before stopping any medication."