What is seasonal affective disorder (S.A.D.)?

Don’t let the winter weather derail your mood or your health goals. Find out what S.A.D. is and how you can avoid it during winter.
Published 8 August 2018

Making a healthy choice is easier when your head’s in a happy space, but remaining upbeat in the face of chilly, rainy winter days can be a challenge. In fact, weather like that can do more than give you a case of the ‘winter blues’ – it can even cause something called seasonal affective disorder. Find out whether you’re at risk and what you can do about it.


What is seasonal affective disorder?


Also known as winter depression, seasonal affective disorder (S.A.D.) is a type of depression related to the change in seasons. “People who experience S.A.D. will notice a gradual depression set in late autumn or early winter, which then alleviates in spring,” says Professor Leon Lack, from the school of psychology at Adelaide’s Flinders University.


Why does it happen in winter?


“Compared to the warmer months, winter days are shorter and tend to contain less sunlight, particularly in southern parts of Australia and New Zealand,” says Professor Lack. Not only can this reduce levels of serotonin, a brain chemical that affects mood, it can also ‘delay’ your body clock, so that your sleep cycle falls out of sync with your daily commitments. “The effect is that falling asleep takes longer and then when your morning alarm goes off at the usual time you feel like you’re being woken up at 3am. When that continues day after day, it contributes to feelings of depression.”


Is it S.A.D. or the 'winter blues'?


Feeling like the weather’s getting you down doesn't necessarily mean you have S.A.D. In fact, while some studies show that around 10 per cent of the population in northern hemisphere countries are affected by S.A.D. to some degree, research carried out at Melbourne’s Swinburne University shows that only about one in 300 Australians experience it.

S.A.D. symptoms include difficulty falling asleep and waking up; feeling sluggish and unmotivated, particularly in the morning; increased appetite; weight gain; and a persistent low, sad or depressed mood. If you notice those symptoms and they worry you, see your GP – a number of treatments are available for S.A.D.


Who is at risk of S.A.D.?


As well as being more common in women than men, a family history of S.A.D. and having experienced depression in the past can increase your risk of the disorder.

“And while S.A.D. is less prominent in this part of the world, people who live in southern parts of the country, where there’s less sunshine and light during winter, may have an increased risk compared to people who live further north,” says Professor Lack.


How can I avoid S.A.D.?


A good place to start is doing what you can to keep your body clock on track as the days grow shorter and darker. As well as helping to prevent S.A.D., it might help you shake the more common winter blues, too. To do it:


1. Don’t sleep in – even on weekends
Grabbing the opportunity to catch up on sleep on a Sunday morning might seem like a good idea but sleeping in will delay your body clock even further, so instead of feeling refreshed on Monday, you’ll feel more tired.


2. Turn the lights down at night
Exposure to artificial light at night inhibits the production of the melatonin that’s required to make you sleepy. “And avoid looking at your computer, phone or other screens, in the hour before bedtime,” says Professor Lack. “As well as the light they emit, the content can stimulate your brain, which delays sleep.”


3. Get some light first thing in the morning
It suppresses your body’s production of melatonin, the hormone that encourages sleep, and makes falling asleep at night easier, too. “Outdoor light is most effective, but if it’s dark outside when you wake up, switch on the lights inside as soon as you get up,” says Professor Lack.


4. Do something active every day
As well as encouraging a better night’s sleep, a 2017 study found that regular physical activity also regulates the expression of a key ‘body clock gene’. Make the most of it by heading outdoors to move – the sun’s ultraviolet radiation is the best natural source of vitamin D, low levels of which have been linked to the onset of S.A.D. Remember to use sun protection when the UV Index is 3 or above.


5. Go to bed on time
While research shows that your ‘wake time’ has more power over your body clock than your ‘bedtime’, whenever you change the timing of your sleep, it can affect your clock’s natural rhythm. Make a conscious effort to avoid those late nights.


5 ‘get happy’ tips to try


When you need a quick fix to give your mood a boost this season, try:


1. Making someone else smile
When you set that as your goal for the day, and do what’s required to make it happen, you’ll feel genuinely happier once you’ve achieved it.


2. Pushing your shoulders back
Shifting your body posture into a more upright, open position improves your mood. Why? Scientists say that ‘positive’ body postures open the same biological pathways that exercise works on to increase happiness.


3. Listening to some upbeat music
Focus on the fact that you’ve chosen that particular track because you’re trying to boost your mood, and it works as an instant ‘get happier’ fix.


4. Giving back a little
Making a small donation to a cause that means something to you or helps you feel more socially connected will make you feel happier.


5. Buy yourself some flowers
People who did that, and positioned them where they’d see them often, as part of a Harvard Medical School study, felt happier and less negative as a result.