How much sleep do you need to be at your best?

Large study reveals seven hours a night - no more or less - is the ideal amount for optimum cognition and mental health
Australian Associated Press

Middle-aged and older people need seven hours of sleep per night for optimal cognitive processing, visual attention, memory and problem-solving, suggests a study using data on almost half a million adults.

The study shows both too much and too little sleep are associated with poorer cognitive performance and mental health,