Seasonal affective disorder: How the dark days of January shape your mood, intelligence and sex drive

Our behaviour and decisions can vary with the changing of the seasons. The trick is to learn to make the most of this natural variation.

The northern hemisphere may have passed its shortest day, but the winter is far from over. After the sparkle of the holiday celebrations, January can feel like the darkest month for many.

It’s not just our emotions that are affected. A , which uses special lamps that mimic the Sun to recalibrate the body clock, although a 2019 Cochrane Systematic Review concluded that the evidence for its The slight dip in mental acuity over winter may amplify existing symptoms of cognitive decline, leading more people to meet the clinical criteria for dementia.

Sociality and sexuality

We may consider our descriptions of “warm” and “cold” behaviour to be merely metaphorical, but . They are also more likely to hunt for dating websites. Once again, many factors are likely involved, but it seems reasonable to speculate that the wintertime peak may, in part, reflect our desire for greater human contact. Whatever the explanation, this variation has real-world health consequences, with further studies revealing a rise and fall in sexually-transmitted infections over the same periods.

With further research, scientists may identify many more cycles in human behaviour that result from the complex interplay of biology and culture. And with this greater knowledge, we can better account for these changes in our own behaviour. By cultivating a more positive mindset, forgiving ourselves for the odd moments of forgetfulness, and making more concrete plans to fulfil our increased social needs, we can all take steps to beat the winter blues and make the most of the new year.

* David Robson is a science writer and author of The Expectation Effect: How Your Mindset Can Transform Your Life, published by Canongate (UK) and Henry Holt (USA). He is @d_a_robson on Twitter.

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