The cold, dark days of winter seem never-ending and you’re struggling. But you can feel better… our expert guide explains how

LANCE WORKMAN IS THE Visiting Professor of Psychology at the University of South Wales, and is an evolutionary psychologist with a special interest in Seasonal Affective Disorder.

By late January, the festivities are a distant memory, spring still feels a long way off and you’re tired, tearful and grumpy. Research suggests around three per cent of people in the UK are diagnosed with full-blown seasonal affective disorder (SAD). But there’s also a milder form, known clinically as sub-syndromal SAD, or ‘winter blues’, which affects 21 per cent of the population. In fact, many experts consider most of us living far from the equator demonstrate some level of mood variability with the seasons.

THE ROOT CAUSE

Our brains are still wired for the bright sunlight of equatorial Africa, where our ancestors came from. Now, not only are we in a colder, darker climate, we’re spending around 93 per cent of our time inside. There’s evidence daylight affects levels of mood-regulating neurotransmitter serotonin, triggering too much in the summer and too little in the winter. We think those with SAD react more strongly to those changes in serotonin. Melatonin, the hormone that makes us feel sleepy when it’s dark, is also involved as the shorter days mean we produce more of this in winter.

WHO’S AFFECTED?

Interestingly, how you feel in winter may not just be about the amount of daylight you get. While most evidence suggests the further you are from the equator, the more likely you are to have SAD, some research doesn’t back that up. I worked on a 2018 study that revealed no significant difference in SAD rates between South Wales and North Cyprus. Intriguingly, people with blue eyes in both populations demonstrated significantly lower rates of SAD than those with darker eye colouration. We know blue eye pigment allows more light to reach the retina and this may allow for a greater production of serotonin in winter. Blue eye colouration might have arisen as an adaptation to SAD and general mood variability at northern latitudes.