Suffering from the winter blues? This is how you tackle seasonal depression

Want to know more about the underlying mechanisms of winter depression? Science editor Gemma Venhuizen answered four questions last year.

3 How many people have it?

About 3 percent of the Dutch population says they suffer from winter depression, another 8.6 percent report suffering from the milder form, according to research by the University Medical Center Groningen (UMCG). In international studies, the percentages vary: between 0.5% and 3% of the global population. People are more likely to report experiencing such symptoms if they live further away from the equator. Winter depression is also more common in women between the ages of 20 and 40.

4 What causes winter depression?

Just like the question of whether winter depression really exists, scientists do not yet have a hard answer to this. It may be that a light deficiency triggers winter depression, but researchers at the UMCG are still not sure after decades of research. It may also have a genetic cause: research shows that people in Canada suffer from winter depression more often than Icelanders, even though they live just as far from the equator.

A third theory says that it is due to the disruption of our day and night rhythm. Our body produces melatonin when it gets dark – which encourages us to sleep. But in winter we are still active for a long time during the dark hours. Evening people, who stay up late and produce melatonin later than morning people, might therefore suffer from winter depression more quickly.

There are also indications that serotonin plays a role: a chemical in the brain that is dependent on sunlight and plays a role in a positive mood. People with seasonal depression seem to have a different serotonin balance than people who do not have that depression.

5 What effect does the transition to winter time have on winter depression?

According to one major theory, seasonal depression has something to do with our internal clock. That clock is regulated by light – we start to feel sleepy the closer we get to sunset. That is precisely why winter time is actually good for us: it is more synchronized with our biological clock, with lots of light in the morning in winter and only a 40-minute difference between solar time and the 'official' time in Amsterdam. During daylight saving time we are much further out of step with the sun: an hour and 40 minutes.

Switching between time zones may also be a problem. This can disrupt your hormone balance, which has an impact on your sleep and your mood.

What exactly does that mean for summer and winter time? NRC answers eight questions, including: How can you be less bothered by changing the clock?

6 Does light therapy work against seasonal depression?

With light therapy, the patient sits in front of a lamp that simulates natural morning light for 45 to 60 minutes in the morning for five days. Such a lamp has a strength of 10,000 lux, while our home and office lamps often remain at 500 lux. Ideally, you start early in the autumn, when the effect will be greatest.

Research from the University of Illinois, among others, shows that people indeed need 'normal' daylight to sleep well at night and wake up well during the day. Light therapy is also a proven effective treatment for winter depression: depressive symptoms often decrease and patients become more energetic. This could be because it 'resets' our biological clock, but researchers wonder whether there is more to it.

Also read: Bright light in the office is good for productivity, but not for our ingenuity. There's nothing like daylight, so go outside during the break if you sit far from a window.

7 What role does our diet play?

Vegetarians seem to get winter blues or depression more often, according to Dutch and Finnish research. But why? It could be related to a deficiency of vitamin B12 and iron. Those who do not consume enough iron become tired more quickly. And people with a B12 deficiency have too little energy in the winter. But here too, no one knows exactly how and why.

Read more: the strange gloom of vegetarians.

8 Does exercise help?

There is little hard scientific evidence for this yet. However, 'outdoor people' seem to suffer slightly less from winter depression. This could be because they spend a lot of time in daylight, or because exercise produces certain hormones that make you happier.

Also read: Experts say walking can help. NRC tips a beautiful winter walk.

9 Do medications reduce the gloomy feeling?

As with other forms of depression, antidepressants are sometimes used successfully for seasonal depression. These medications influence messenger substances in the brain that, among other things, determine mood. Cognitive behavioral therapy can also work well.

10 Blue Monday: sense or nonsense?

We can be brief about Blue Monday: that is nonsense. There has never been a study that shows there is a specific 'most depressing day of the year'.
Blue Monday was invented by a doctor who worked with a tourist agency. Read here how he did that.

And maybe we should just accept that winter depression is part of life. At least that is what British writer Katherine May thinks. We just have to learn to enjoy the dark moments, she says.