Sleep and cognition: or, your brain needs sleep!

Most people are likely to be familiar with the expression "sleep on it" - meaning that sleep can be beneficial to problem solving and decision making.

Emerging evidence shows that sleep is even more important to brain health and cognition, particularly memory, than we realise.

It has been known for some time that sleep apnoea, a sleep disorder, is a risk factor for certain types of dementia.

A new Australian study has found that another sleep disorder is associated with memory problems. People with rapid eye movement sleep disorder (RBD) have twice the risk of developing memory problems and Parkinson's disease. RBD is a sleep disorder that involves abnormal behaviour during the sleep phase where rapid eye movement occurs. People with RBD tend to act out their dreams.

The study found that a third of the people with RBD developed mild cognitive impairment or Parkinson's disease within four years of being in the study. This is a rate that is more than twice that of people without RBD. Behavioural neurologist Dr Brendon Boot was the lead author of the paper, which has been published in the Annals of Neurology.

He says being able to identify those patients who are a greater risk of mild cognitive impairment or Parkinson's disease will mean earlier treatment for those affected.

Early invention is vital because as these disorders advance they destroy brain cells.