SAD – Seasonal Affective Disorder

Birds, mammals, rodents and amphibians; all animals react to the changing seasons in some way. Humans are no exception. Have you ever found you have more difficulty waking in the winter? More tempted to snack on unhealthy foods and feel the pounds pile on even as you attempt to diet? Do you find it harder to focus at work or in relationships? Or maybe you feel down in the dumps or, worse still, depressed? If you answer yes to any of this you could be one of the millions of people across the world who have difficulty adjusting to the changing seasons. For some of these people the symptoms are severe enough to disrupt their lives and cause considerable distress.

 

Standard figures show that 2% of people in Northern Europe suffer with SAD with another 10% developing the milder ‘Winter Blues’. Across the world the incidence increases with distance from the equator, except where there is snow on the ground, when it becomes less common. More women than men are diagnosed as having SAD. Children and adolescents are also vulnerable. The symptoms tend to start from around September each year lasting until April, but are at their worst in the darkest months.

 

The causes are still not fully understood but we know the problem stems from the lack of bright light in winter. The nerve centres in our brains controlling our daily rhythms and moods are stimulated by the amount of light entering the eyes. During the night, the pineal gland produces a substance called melatonin which makes us drowsy. At daybreak, the bright light causes the gland to stop producing this melatonin. But on dull winter days, especially indoors, not enough light is received to trigger this waking up process. More recently, good evidence has been found to link exposure to bright light with the increased production of a substance called serotonin. Serotonin is a neurotransmitter, ie it carries signals from the output of one nerve to the input of the next inside the brain. Lack of serotonin is known to be a cause of depression, and indeed this maps well onto what people say: tasks which are easy when you are well become frustratingly difficult when you are depressed.

 

It is therefore sensible to suggest the treatment for such a disorder where lack of light is the issue would be to introduce artificial bright light. It would be even better to suggest people suffering take a holiday in a bright sunny country but unfortunately this is often not viable. The light needs to be at least 2500lux (a technical measure of brightness) which is 5 times brighter then a well lit office and a normal living room can be as low as 100lux. The light does not need to be special daylight, ‘full spectrum’ or colour matching. The preferred level of light is about as bright as a spring morning on a clear day and for most people sitting in front of a lightbox, allowing the light to reach the eyes, for between 15 and 45 minutes daily will be sufficient to alleviate the symptoms. The user does not have to stare at the light, but can watch TV or read or similar so long as the light is able to reach the back of the eye.

 

If you feel like any of the above applies to you then light therapy may well be the answer. A company specializing in light therapy (http://www.outsidein.co.uk) offer a 21 day home trial to anyone wishing to try light therapy. Light therapy devices are also VAT free for personal use.

This is a members article written by Madzwalker