No need to be SAD

Since December 22 the days have been getting longer, though it may not feel like it. Especially for those of us who get up in the dark.

If a retreat under the duvet as the alarm goes off sounds familiar, you are not alone. According to the Mental Health Association, 45 per cent of us feel like hibernating at this time of year, with young people and women the most affected.

However, a craving for sugary or starchy foods, an increase in alcohol consumption, a loss of libido, increased need for sleep and a persistent unhappy, anxious mood are symptoms of a more extreme form of the winter blues: a form of depression called Seasonal Affective Disorder (SAD).

Sleep pattern shift

SAD isn't totally understood but it's believed that as the seasons change and sunlight decreases, there is a shift in our circadian rhythm (sleep/wake pattern).

Because we don't shorten our working hours to fit the truncated hours of daylight (petition your boss now), our biological clocks become out of sync with our daily patterns. We may all experience SAD from lesser to extreme degrees as our bodies struggle to adjust to the lack of light.

The culprit here is melatonin, a hormone secreted by the pineal gland of the brain that makes us drowsy. In the dark, melatonin production is stepped up, making it difficult to get up on dim mornings. Bright light suppresses its production and increases that of serotonin, a neurotransmitter that relays signals between the nerves in the brain. Low levels of serotonin have been linked with depression.

Research suggests that light entering the eyes has a direct influence on brain chemistry and can reset a sleep cycle. SAD can be eased by exposure to light, preferably natural winter sunlight.

Spells in sunny climates or outdoor exercise can both help to relieve mild symptoms of SAD. But these are not always practical.

In this case, phototherapy - where a light box emits very bright light through a UV filter while you read or watch TV - may be an option. The light is 20 times brighter than your office and equivalent to a clear, spring morning. Between 15 and 45minutes' exposure is said to alleviate depression.

But how does this help with getting up in bleak darkness on winter mornings? Enter the 'dawn simulator', a lamp programmed to gradually increase its intensity so that by the time you wake up you are bathed in a sunny glow and have, hopefully, acquired a similar disposition.

Sunny days ahead

I tested the Lumie Bodyclock Advanced, a combined alarm clock and lamp with a choice of a 15, 30, 60 or 90minute wake-up time.

Waking to a bright yellow globe and a gentle pipping noise was a welcome change from being violently jolted from my dreams by my usual device. The experience felt similar to waking on a sunny Saturday in June. The snooze button meant an instant fade and a nine-minute sunrise.

The Lumie also has a sunset option which, with a disappearing glimmer, lulls you gently to sleep. It would be particularly useful for those who struggle to hit consciousness, do shift-work or experience jet-lag.

While I'm not yet leaping from my bed with unbridled enthusiasm, after a week my brain has learned that light means wake-up time. I feel more alert and my mornings have been transformed from melancholic to positively luminous.

Lumie Bodyclock Advanced, £99.95. Tel: 0845 658 9292, www.lumie.com For a booklet on coping with SAD and the winter blues contact MIND. Tel: 020 8221 9666, www.mind.org.uk