Last weekend I went to a day of talks on sleep and dreaming. Russel Foster was discussing the importance of day time light on our sleep rhythms and how sleep impacts on our mental health. He started by talking of the importance of light for the body to create a healthy circadian rhythm. The circadian rhythm is the internal body clock that regulates when we feel tired and helps us to fall asleep at night. When it is out of balance our sleep cycle can be disrupted and it seems that a lack of day time day light can have a huge impact on disrupting our circadian rhythm.
The information he shared was really quite simple but if applied can have such a huge impact on our well being. SAD is the condition of feeling depressed due to a lack of light exposure during the winter. The image above shows a study where people with SAD were exposed to a placebo in the form of an air ioniser, a dawn simulator in the form of a light that gradually gets brighter in the bedroom at the time of waking, and exposure to SAD lights in the day. As you can see by the end of the study those who had used the SAD lights had seen a big improvement, whilst the dawn simulator also had benefits, and the ioniser had limited benefit.
How to use SAD lights then to gain these benefits? The speaker went on to look at a study in a nursing home where lights which mimicked sun light were installed and the results were a noticeable improvement in the sleep patterns of the residents and their sense of alertness in the day. This is because for the circadian rhythm to be well balanced we need to experience light in the morning so the body can register that it is day time. We often work in offices with lighting that does not give the required amount of brightness to stimulate the circadian rhythm and when we are outside in the Winter we are often traveling to work and go home in the dark. As a result our internal clock is not being set to trigger a healthy sleep pattern. As we then do not sleep well enough to feel rested we may then use caffeine to wake us up, but the impact of this is to leave us too alert by the end of the day to sleep so we may use a sedative such as alcohol or sleeping pills which results in not sleeping well, so we need caffeine in the morning to get us going…..and so the cycle goes on.
The results from the nursing home show what happened to sleep when the new lighting was installed. The brightness of the light is measured in a unit called lux, which you’ll see reference in the photos below. The normal lighting only provided 20 lux. The new lighting provided 2000 lux.
As you can see, once the light had been increased to 2000 lux the sleep patterns of the residents all became much more regular, with people sleeping throughout the night. It also improved the symptoms in people with dementia.
Below is a list of possible side effects of lack of Winter day time light:
As the study I referenced at the start of this article outlines, use of SAD lights can dramatically help reduce these symptoms. If you want to try light therapy for yourself you can look for SAD lights in your local light shop or online. Then use them for at least 30 minutes in the morning as you sit at your desk or whilst eating breakfast if you have time to sit for 30 mins.
The speaker went on to say that as well as SAD these lights have also been shown to help with clinical depression. The image below shows the impact of using prozac as compared to using light therapy.
Fluoxetine is a name for Prozac, an anti depression medication. As you can see light therapy alone was significantly more effective than the drug, whilst when combined with the drug it had even more of an impact on the level of depression. Interestingly the placebo was nearly as effective as the anti-depression medication! This suggests that rather than assuming people need medication for depression using light to regulate the body may be as powerful, especially if then combined with mindfulness in the form of the MBCT programme. (Mindfulness Based CognitiveTherapy). It also raises the question of how much of clinical depression and our struggle with trying to find out what is ‘wrong’ with us might be resolved by simply giving ourselves enough light so that the body’s internal mechanisms can come into a healthy balance. If you want to try this look for a SAD light that provides at least 10,000 lux and use for 30 minutes in the early morning.
Here’s wishing you some brighter days!