Does ‘January brain’ actually exist?

Even for the most self-disciplined of self-starters, January is an endless, lethargic struggle. But does the cold, dark first month of the year really make our brains work differently? Katie Rosseinsky finds out

Zoning out at your computer screen as you try to tackle the mountain of emails that have piled up since the Christmas break. Frantically searching in the depths of your mind for the right word but never quite finding it. Maybe even putting things in the fridge that definitely don’t belong there.

Welcome to the January doldrums, when precisely no one, not even the type of rise-and-grind hustlers who voluntarily listen to the Diary of a CEO podcast, seems to be on their A game. When we get back to work after that strange, glorious post-Christmas hinterland period, many of us struggle to adjust. Our brains might feel foggy, our motivation lacking, and we’re likely to seriously struggle to match our usual productivity. 

Lethargy: do the seasons really impact our brain? (iStock)

Let’s call that befuddled sensation “January brain”: a general sense of mental sluggishness, as if we’re operating on a slight time delay or in slow motion. These feelings aren’t necessarily confined to our 9 to 5s either. The other day I genuinely struggled to process a contestant’s (admittedly quite convoluted) logic on The Traitors and had to rewind their explanation about three times to work out what he was on about. And socialising? It’s barely worth contemplating when stringing a coherent sentence together feels like hard labour.

All of this, of course, comes at a time when we’re meant to be emerging from our festive cocoons to become the best, healthiest versions of ourselves – and that disconnect between what we want to achieve and what we’re actually capable of managing right now can be seriously dispiriting. No wonder one in five people ditch new year’s resolutions after less than a month, according to recent research from Forbes Advisor. But why exactly do so many of us feel so torpid and stagnant at this time of year? 

It’s long been accepted that animals adapt to the seasons: they might migrate during the winter, or transform the colour of their fur. Some mammals even undergo changes in the brain. “In hibernating animals like squirrels, part of their brain gets Alzheimer’s-like pathology in it during hibernation,” says Professor Tara Spires-Jones, deputy director of the Centre for Discovery Brain Sciences at the University of Edinburgh and president of the British Neuroscience Association. “But that goes away when they wake up.” And to conserve energy when it’s cold, shrews’ brains shrink, leaving them worse at navigation. (You could say they’re less shrewd in the winter… can I blame “January brain” for dad jokes, too?)

The impact of the seasons on human brain power has not yet been explored so extensively but there are a handful of studies which have delved into this phenomenon. In 2016, researchers at the University of Liege in Belgium assessed the brain function of 28 participants throughout the year. Each of the volunteers would spend four and a half days inside a laboratory, and at the end of that period would take part in two tasks designed to test attention span and memory. Their brains were scanned with an fMRI machine, to detect changes in blood flow due to brain activity.

Winter blues: a lack of light can seriously impact our mood (iStock)

The researchers eventually found that activity relating to attention peaked in June, around the summer solstice, and was lowest near the winter solstice in late December. So, essentially, our brains do work differently depending on the time of year. In particular, they discovered “significant annual variations” in the thalamus and amygdala, the parts of the brain involved in alertness, and in the hippocampus and frontal areas. Both of those help with self-control, problem solving and reasoning. All the things you pretended you were good at in your job interview, basically. Memory-related activity, meanwhile, peaked in the autumn and dipped around the spring equinox in late March.

What’s interesting is that the test scores didn’t vary much throughout the year. The outcome was similar but the process of getting there was different. “Because the means at [our] disposal to complete cognitive processes is lower in winter, it could feel harder to complete them,” the study’s co-author Dr Gilles Vandewall told The Daily Telegraph. So perhaps it just seems more difficult to get stuff done in January but we’re actually doing OK? These variations, Vandewall also suggested, could be a throwback to a time long before electric light and central heating – when we were much more in tune with the seasons.

You don’t have to comb through academic studies, though, to agree that the mornings are dull and gloomy right now: throw open your curtains at, say, 7.30am and you’ll still be greeted by near-darkness. Light (or the lack of it) can affect our brain and our wellbeing. “Every cell in your body has a molecular clock,” says Professor Spires-Jones. “The master regulator of these clocks is in the brain, and it’s called the suprachiasmatic nucleus.” When it gets information about light through the eye’s retina, it tells the body that it’s time to get up. “And that controls things like sleep and waking, activity, feeding and reproduction”, Spires-Jones says. Not getting enough light, then, can throw all this off-kilter, impacting our mood and sleep schedules.

Sunlight exposure is known to trigger the release of serotonin in the brain

Professor Zoltan Sarnyai

Those dark mornings are especially tricky to shake off: in fact, they might even set the tone for the rest of the day. “Waking up is the most stressful, taxing part of the whole day,” explains Dr James Jackson, reader in psychology at Leeds Trinity University. “You release stress hormones and sugar goes into the blood, which starts to power you. The amount that’s secreted out at that time, maybe 30, 40 minutes after you wake up, basically decides how much energy you have for coping with things for the whole rest of the day.” But if we’re getting up when it’s pitch black outside, we lack stimulus. “We don’t have the same reactions and we don’t see the same resources – it’s difficult to get going.” I’ve always known that starting my day lying in bed in near darkness scrolling through Instagram (usually watching effortlessly radiant women showing off their morning routines) wasn’t the healthiest of starts. But I’d never joined the dots to link it to my lethargy later on. 

Light also impacts our hormones. “Sunlight exposure is known to trigger the release of serotonin in the brain,” says Professor Zoltan Sarnyai, a Harvard-trained neuroscientist and chief scientist at nutraceuticals company Ally Sciences. “Serotonin is often referred to as the ‘feel good’ neurotransmitter because it contributes to feelings of wellbeing and improved mood.” Less exposure to sunlight, he notes, could lower serotonin levels, “which can in turn impact mood and contribute to depressive symptoms” (it might play a role in seasonal affective disorder too). At the same time, “the longer periods of darkness in winter can increase the production of melatonin, the hormone that regulates sleep,” adds Ivo Vlaev, professor of behavioural science at the University of Warwick. Hence those feelings of lethargy. 

The sudden return to routine can feel anticlimactic

Professor Ivo Vlaev

Beyond these factors, though, “we’re also regulated by social cues – meal times, work schedules”, Spires-Jones says. So if we spend a week or more lazing around in a cosy festive limbo, “that changes the regulation of these sleep-wake cycles and body clocks. And so that affects not only when we wake up and are active but our activity levels and our moods.” Similarly, “the sudden return to routine”, plus fewer social gatherings as everyone tries to quit drinking and save money, “can feel anticlimatic” post-Christmas, Vlaev says, “contributing to a sense of sluggishness”.

It’s also a time of year when we’re bombarded with confected concepts like “Blue Monday” (branded the most depressing day of the year as a marketing ploy for Sky Travel to push winter holidays on consumers 20 years ago). Might our perceptions of our own “January brain” be influenced by these messages? Humans can be prone to misattribution. “When we feel a certain way, we don’t know why, we just guess,” Dr Jackson says. “It’s all about mental shortcuts in order to view the world in a way that tends to work.” 

Beyond recognising the power of these cultural cues, how can we alleviate a case of “January brain”? The answers are probably all things that you know, deep down, will lift you out of a funk. More natural light (to boost those serotonin levels). More exercise, especially outdoors. Vitamin D. A regular sleep schedule. Not reaching for your phone first thing in the morning (sigh). Even just making sure you don’t enter full-on hermit mode, despite how tempting the sofa might seem, is a good step (positive social interactions can promote the production of oxytocin, another “feel good” hormone). And perhaps we just need to give ourselves a bit of compassion and see the funny side when we put the milk back in the cupboard and the mug back in the fridge for the seventh time this month.