For sale: light therapy by the hour; SAD: key treatment to be made

0 Comments | Sunday Herald, The, Sep 12, 2004 | by Jenifer Johnston

Lead scientist, Dr Gerald Lincoln, of the MRC's Human Reproductive Sciences Unit, said: "Our moods, appetites and energy levels are affected by the seasons. Unravelling at a molecular level what makes our seasonal clocks tick is important for treating seasonal and lifestyle-related illnesses and diseases."

Other research from Canada suggests that poor fluorescent lighting in badly lit offices can bring on SAD and that exposure to sunshine can reduce stress and pain in hospital patients. Sunshine also produces vitamin D in the body which is vital for calcium absorption.

Elinor Jayne of the Scottish Retail Consortium told the Sunday Herald that Buddhafield is one of a number of high street "destinations" people are now using to improve their health.

what's in the box Lightboxes stimulate the level of light you might find on a clear spring day - a daily treatment of 15 to 45 minutes is thought to be enough to keep symptoms of SAD at bay.

Staring directly at a lightbox is not required, but the light must be at least 2500lux (lux is the technical measure of brightness) - about five times as bright as a well-lit office.

At 2500lux, sessions of two hours a day are thought to be beneficial, at 10,000lux only 20-30 minutes is necessary. The light does not need to be special daylight, colour matching or full spectrum light, and in fact rearranging lights in a room to optimise their brightness can help.

Researchers are still investigating the tiny risk posed by lightboxes to those predisposed to skin cancer.

SAD but true?

Seasonal Affective Disorder mainly affects people living in northern Europe and Canada, where daylight in the winter months shrinks to just a few hours a day. Countries with little or no snowfall in the winter seem to have more sufferers because of less reflected light.

Research puts about 2% of the population of northern Europe "suffering badly" from SAD, with another 10% putting up with milder symptoms of the winter blues. While the exact causes of SAD are still being investigated, it is known that the amount of light entering the eye stimulates nerve centres in our brains. At night the pineal gland produces the hormone melatonin, which makes us drowsy. At dawn bright light causes the gland to stop producing melatonin. But on dull winter days, especially indoors, not enough light is received to trigger this process.

Exposure to bright light is now associated with the increased production of serotonin - a neurotransmitter. Depression is associated with low serotonin levels.