Are you having to try hard to put on a happy face? For many of us, January can be the most miserable month of the year. We return from the Christmas and New Year break several kilograms heavier and feeling sluggish, struggle to align with the rhythm of work, fall victim to the flu, and lose patience with the cold.
Seasonal affective disorder or SAD is a mood disorder that can affect some people during winter. It is thought to be triggered by a combination of factors that revolve around an anomaly in our 24-hour daily rhythm, or “circadian” rhythm. These include disturbances in melatonin and serotonin levels and a disruption to the circadian cycle.
A decline in vitamin D over the winter months is also implicated, perhaps partly because vitamin D influences an enzyme called tryptophan hydroxylase 2, which helps to turn the amino acid tryptophan into the neurotransmitter serotonin, which in turn can be converted into melatonin.
SAD is not, however, the sole cause of the winter blues. The euphoria and buzz of the holiday season gives way to a lonely and empty hiatus; viral infections leave us in a state of inflammation which can induce depressive symptoms; and, according to a psychological theory known as “social thermoregulation theory”, feeling physically cold can actually make us feel lonelier.
Regular exercise is a natural and effective antidepressant, as most of us know. Here are three more ways to break into a smile and raise your mood if you are feeling a little low this season.
1. Check your clock
You might have used the hormone melatonin to help with jet lag, but its effects extend beyond that. A disturbance in melatonin levels can affect mood and may worsen symptoms of depression. The pineal gland in the brain releases melatonin during the night in response to darkness, and too much or too little melatonin, or melatonin at the wrong time, can be associated with a low mood.
If you don’t get exposure to daylight in the morning, your pineal gland does not get the signal to curtail its production and this can worsen symptoms of depression. This is why morning bright light therapy is sometimes prescribed for SAD. Daylight exposure enhances melatonin release at night, but blue light or bright light prevents its normal release in the evening.
To regulate your melatonin cycle and circadian rhythm, get as much daylight as possible during the day and dim your lights as soon as the sun sets in the evening.
Food and exercise belong with daylight. Get half an hour of daylight after breakfast every morning and avoid large meals or heavy exercise late in the evening. Use blue light filters on electronic devices in the evening and if you are working late, wear blue-light blocking glasses.
2. Eat right
The most recent systematic review and meta-analysis of the relationship between diet quality and depression published in the Journal of Affective Disorders this month found that eating fish and vegetables is associated with a lower risk of depression.
Another recent randomised controlled trial, the ‘Smiles’ trial, found that switching to a varied diet that is entirely free of processed foods reduced depressive symptoms in the setting of moderate to severe depression. Part of this effect may be attributed to processed food and additives harming the gut microbial flora.
Some studies show that taking probiotics for a period of time can improve mood and stress reactivity, so including probiotic foods such as natto, miso, or natural yogurt in every meal is a wise move.
Increasing your quota of omega-3 fatty acids may improve your mood, particularly if you are inflamed. Good sources of these include oily fish and seafood, flax and chia seeds, walnuts, and soybeans.
An animal study published in Nature Immunology last month also showed how a large immune response to a virus can lead to virus-fighting blood cells isolating the amino acids tryptophan and tyrosine. The brain needs these to make serotonin and dopamine, so this can affect mood. Tryptophan and tyrosine are found in good sources of protein. Eating oily fish covers both bases.
3. Get hot
Some psychological studies point towards a relationship between physical warmth and emotional well-being, such that a fall in one may be buffered by a rise in the other. This may have arisen from the practice of huddling together to keep warm, which carried the psychological security of tribal support.
A randomised, controlled, double-blind study published in JAMA Psychiatry last summer showed that raising the body’s temperature just once (such as with a sauna session or a hot bath) can reduce depressive symptoms for up to six weeks afterwards.
In another randomised trial published in BMC Complementary and Alternative Medicine last year, taking a hot bath at 40 degrees Celsius twice a week significantly reduced symptoms of depression after just four weeks.
If you are normally not tempted by a sauna, hot bath or a hot yoga class in Hong Kong’s usual heat and humidity, this might be a good time of the year to make an exception.
Late US president Theodore Roosevelt once wrote of his own tendency towards melancholy, “Black care rarely sits behind a rider whose pace is fast enough”. He overcame his struggle with depression by being in a constant state of flux, launching into new projects and embracing new challenges with vigour.
“Believe you can and you’re halfway there,” and, “It is hard to fail, but it is worse never to have tried to succeed,” are two other gems of wisdom he imparted. And this one, that will make you smile: “If you could kick the person in the pants responsible for most of your trouble, you wouldn’t sit for a month.”
Rumination – focusing on the symptoms of our distress, rather than on a solution – contributes to depression. It is difficult to ruminate if your attention is absorbed by what you are doing.
By its nature, Hong Kong, with its energetic pace and momentum of progress, offers a powerful antidote to winter blues. Our winters are warmer and brighter compared to many other parts of the northern hemisphere that lie at a similar latitude. If that isn’t enough, there’s always Lunar New Year right around the corner.
Doctor and researcher Mithu Storoni is the author of Stress Proof – The Scientific Solution to Building a Resilient Brain and Life. Before moving to Hong Kong, she was a clinical research fellow at the National Hospital of Neurology and Neurosurgery in London.