Many experts now believe that lots of people who live in the Northern Hemisphere are 'light deprived' and this may be the reason for the increase incidence of Winter Blues or Seasonal Affective Disorder (SAD).
Why is this?
In a nutshell, it is because our lifestyles and working practices and places have changed greatly over the last several decades. Consequently, more people than ever:
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Work indoors - often for long hours and sometimes in offices without access to natural light. It is not uncommon in the winter for people to travel to work in darkness or dim light, spend all day inside and not leave work until it is dark again, meaning exposure to natural daylight during the work week is minimal. This also applies to many school children and students. Shiftworkers also have significantly reduced daylight exposure due to their working hours.
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Relax indoors - outside of work hours, we watch TV, exercise inside artificially lit gyms, sit inside coffee shops and of course, these situations occur even more in the colder winter months. Elderly people who are not able to get out very much often have signifcantly less light exposure.
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Play indoors - Children and teenagers spend more hours than ever playing on computers or watching TV inside and less time playing outside.
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Travel indoors - Most forms of travel are without natural light e.g. Underground, buses, trains, airport terminals, airplanes and in winter time, many travel when it is dark. This is particularly applicable to frequent business travellers who also have their body clocks disrupted. In the past, more time would have been spent travelling outside, either on foot, by carriage or on ships.
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Wear Sunglasses - Fashion and changing habits mean that many put on sunglasses immediately when out in the sun even when the sun is not at its peak, reducing light levels the eye is exposed to.
- Perceive the sun as 'bad' or 'unhealthy' - Whilst it is true that the UV radiation prooduced by the sun can cause skin damage and with prolonged exposure increases the risk of skin cancer, we also need light and our skin exposed to a certain amount of sun to maintain good mood and vitamin D levels.
It is therefore very likely that many people will have a low level of bright light exposure on most days, especially in the winter months.
Why does low light exposure cause mood changes and depression?
When bright light hits the human eye, it triggers changes in certain chemicals in the brain. Significantly reduced light has a dramatic effect on two key brain chemicals called ‘serotonin' and ‘melatonin'. Serotonin, our ‘happy, alert' hormone decreases whereas melatonin, our ‘sleepy' hormone, is increased. The result is tiredness and low mood or lethargy, as well as other unwelcome effects. This is not really a problem in the evening, when it is natural to begin to wind down and get sleepy, but when these chemical changes occur in the daytime, for some it can seriously affect their mood, concentration and productivity.
When this happens during the autumn and winter months, particularly in the UK and mainy parts of Europe where the skies are often overcast which further reduces bright light, the symptoms produced are known as Winter Blues (the milder form) or Seasonal Affective Disorder (SAD).
How can I find out more about SAD and Winter Blues?
You can find out more information about SAD and Winter Blues on our dedicated website, www.litebook.co.uk. The Litebook is a revolutionary SAD light for which Intus Healthcare are the exclusive UK distributors of. For that reason we have spent a great deal of time researching SAD and putting together a comprehensive website that is full of information for SAD and Winter Blues sufferers. |
