A real-life study has confirmed the devastating effects of not getting enough sleep.
Researchers who carried out an in-depth survey of more than 1,000 British adults found that poor sleep leads to fading memory and a heightened risk of depression, anxiety and stress.
People who slept for less than five hours a night struggled to function effectively the next day, the research showed.
They could not remember where things were and forgot to carry out simple planned tasks such as posting letters or taking medication.
Dr Anna Weighall, from the University of Leeds, who presented the findings at the European Society of Cognitive Psychology's annual meeting in Potsdam, Germany, said: "A lot of previous sleep research has been based on lab studies.
"This is the first time we have surveyed people in their everyday lives.
"What is emerging is the debilitating impact of poor patterns of sleep.
"People who are not getting enough sleep are at risk of experiencing a much lower quality of life and it hinders their ability to function effectively when they are awake."
The analysis found a statistically significant relationship between poor sleep and reduced mental well-being, and a strong link between lack of sleep and everyday memory problems.
The associations were even stronger in people who regularly slept for less than five hours per night.
Dr Weighall said: "There is now a very compelling case to say there is a strong relationship between getting a good night's sleep and experiencing better health, well-being and memory function."
