Professor Gaby Badre, a consultant at the London clinic and a professor at Sweden's Gothenburg University, records the brain activity of financial workers who come to him with sleep complaints. A number of them suffer from long-term sleep deprivation as a result of choosing to cut back on sleep in order to fit more into their busy lives.
It is not entirely clear whether the higher incidence of sleep complaints in western societies is due to greater awareness and better detection, or because of changing work and life patterns. According to Dr Louise Rayner of Loughborough University, what has increased is the complexity of tasks that people have to do in their jobs, the performance of which is more likely to be affected by sleep deprivation.
The results of chronic ‘sleep debt' include hormonal defects, decreased immunological function, high blood pressure, cardiovascular problems, weight gain and type II diabetes, according to Prof Badre. Modern working habits are pushing human physiology to its limits, he believes.
The added problem of increasing obesity is giving rise to higher incidence of obstructive sleep apnoea (OSA), which causes severe breathing problems in the night and fatigue during the day. This condition affects about four in 1000 people in the UK, up from one in 1000 15 years ago.
Prof Badre has seen a number of clients, mainly City high flyers, who use drugs to stay awake for days at a time during intense periods of work. This kind of behaviour leads to cognitive dysfunction, as they lose out on normal sleep cycles that enable tissue repair to take place.
Sleep deprivation can also lead to a neurological condition called REM behaviour disorder, which causes sleepers to injur themselves and partners. Unfortunately many of the afflicted are either unaware or too embarrassed to take steps to restore the healthy ‘Circadian rhythms'.
Recommendations for healthy sleeping include:
Going to bed and getting up at the same time every day, including weekends.
Avoiding drinking caffeine in the evening or taking hot baths late at night
Making sure to get an optimal amount of 'core sleep': about six hours for most people, supplemented by naps during the day.
Drinking alcohol will deprive your brain of the cycles it needs to make you feel refreshed the next day.
Do not rely on sleeping drugs over the long term - bad sleep is a symptom of stress that needs treatment.
It's normal to feel sleepy after lunch but if you find yourself feeling sleepy throughout the day, seek medical advice.
Dreaming of a good night's sleep
FT, 24 April