Ten years ago Vicki Childs realised she wasn’t feeling herself every time winter came around.

“I would just feel really weird, low and lousy — it was a new feeling to me.”

The registered counsellor, who lives in Sydney, said she felt a sudden drop in motivation and a sense of doom.

“I just wanted to hibernate, and as someone who runs four different businesses, that’s really unlike me.”

She felt there wasn’t as much “joy left in life” but the symptoms always subsided when the season changed.

Vicki Childs said she used to dread every winter.(Supplied: Vicki Childs)

Vicki had no history of depression but after a few winters like this, she was diagnosed with seasonal affective disorder (SAD), more commonly known as seasonal depression.

Learning about the condition was a huge relief and she’s gone on to counsel clients who also have SAD.

“I’ve had a lot of clients come in concerned because they’ve not had any mental health issues previously and suddenly in the cooler months they feel really depressed and struggle.”

What is SAD?

Seasonal affective disorder is a type of clinical depression that presents only in specific seasons for at least two consecutive years.

Symptoms last for more than two weeks and can include:

  • a depressed mood for most of the day or nearly every day
  • diminished interest in activities which are normally enjoyable
  • hypersomnia (excessive sleepiness)
  • hyperphagia (extreme hunger)
  • weight gain

A hallmark sign someone has SAD is their symptoms completely dissipate when the season changes.

Researchers are still determining what causes SAD but the best theory is that when we get less sunlight in winter, our circadian rhythm (internal body clock) can get out of sync.

“There’s a change in the amount of light which seems to trigger some sort of change in our biology, our hormones and our neurotransmitters,” Nickolai Titov, a professor of psychology at Macquarie University, said.

Research has shown people with SAD have lower levels of the neurotransmitter serotonin — known as the feel-good chemical — during winter but serotonin activity bumps back up in the warmer seasons.

If someone believes they may have SAD they should see a mental health professional, Professor Titov said.

“I certainly wouldn’t be self-diagnosing because you need to look at the broader picture of what’s changed in your life.”

SAD is not considered a standalone mental disorder, but it is included in the most recent International Classification of Diseases under the category of recurrent depression.

It’s diagnosed more often in women than men and severity of symptoms can differ, with daily functioning impaired for some people, but not others.

It can also rear its head in summer and, although rare, it has been recorded among people who live in Townsville, North Queensland.

SAD down under, yes it happens

SAD is well documented in the northern hemisphere — an estimated 12 million people in northern Europe are affected.

And although Australian winters can be more mild, some experts believe we need to take the disorder more seriously here.

Psychiatrist and University of Tasmania researcher Adriana Nevarez-Flores, who lives in Hobart, decided to look into SAD in the southern hemisphere after noticing people around her exhibiting signs of depression every winter.

Her research compared 13 papers on its prevalence in Australia and found rates were comparable to those in certain parts of the northern hemisphere.

“Prevalence around the world is between 1 and 10 per cent and in Hobart we found it was at 9 per cent. This was comparable to the prevalence in Bologna, Italy,” Dr Nevarez-Flores said.

People in Hobart have recorded the highest rates of SAD in Australia.(ABC News: Luke Bowden)

Unsurprisingly, those in the southern states, particularly Tasmania, were found to be at the highest risk.

 But data is limited and Dr Nevarez-Flores believes SAD could be more common than we think.

“It is an important medical condition that has likely been under-recognised in Australia.”

Because SAD was not a standalone mental disorder people might be incorrectly diagnosed with depression and not understand the seasonal link, she said. 

Alternatively, people may be accustomed to feeling depressed in winter so they just ignore symptoms and battle on.

“But a depressive disorder needs to be identified and treated early, even if the symptoms aren’t that bad initially, as there may be a point where they do interfere with work and relationships,” Dr Nevarez-Flores said.

Professor Titov, who heads up MindSpot, doesn’t believe data on SAD in Australia is strong enough to point to a “significant” health issue.

The most recent study is from 2004 and some research may have been compromised by confirmation bias.

“People often volunteered to answer questions about seasonal symptoms and arguably the people who are likely to do that felt they had the symptoms,” he said.

He advised mental health professionals to carefully examine any changes to a patient’s routine before making a diagnosis of SAD.

“We know people who struggle during winter often report they’re not actually doing the things they would normally do during the warmer parts of the year, like exercise or socialise as much.

“That doesn’t mean they have developed depression, it could just mean they’re unstimulated and maybe a bit bored.”

Light boxes and other treatments

The treatments for SAD are the same as for other depressive disorders and include antidepressants and psychotherapy.

Phototherapy, or bright light therapy, is also recommended by the Royal Australian College of Psychiatrists as a first-line treatment for SAD.

It involves sitting in front of a specially designed box that emits full-spectrum light with your eyes open. Some people eat, read or work while sitting in the light.

Light therapy is best done first thing in the morning.(Getty Images: Santiago Urquijo)

The College considers it a monotherapy, which means it can work without being accompanied by other treatments, such as anti-depressants.

Controlled placebo studies have shown a difference in symptoms after two weeks of using a 10,000 lux (a measure of light intensity) light for half an hour each morning.

“There are technical specifications around the time of exposure and frequency so it’s important to be guided by an appropriately trained health professional when buying one though,” Professor Titov said.

Vicki Childs noticed an improvement in her symptoms six weeks after continuous use of a light box but she also incorporated more exercise into her routine, which is another proven treatment for depression.

Dr Nevarez-Flores now wants to undertake a three-year study with participants all over Australia to get a better understanding of how SAD differs by location.

“It’s worth pursuing this, the weather isn’t going to change but we can do something to improve the lives of Australians.”

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