Seasonal affective disorder (SAD) has been recognised since the 1980s and was originally considered a condition of its own, but more recently has become regarded as a subtype of major depression disorder, which is clinically significant depression.
Symptoms are often very similar to major depression, but include disruption to sleep cycles including fatigue in the morning, more craving for carbohydrates and rich foods with associated weight gain, and people tend to exercise or engage in activities less.
In terms of triggers, SAD seems to be related to changes in natural light, which is why it's mostly associated with the winter months. The changes in light affect our hormones, which include cortisol and melatonin and potentially some neuro transmitters – the chemicals in the brain that facilitate communication across neurons, including serotonin and others.
The first step for all of us at this time of year is to take a few minutes to reflect on our daily routines.
But an important point, particularly in countries such as Australia, is that we need to be cautious about assuming the winter blues we can all experience is actually a clinical disorder. Yes, there's less daylight in winter, but even on winter solstice, around June 21, most parts of Australia are still getting still at least 10 hours of sunlight.
In contrast, very northern or southern parts of the world in winter might not get any light at all – so the triggers and risks for seasonal affective disorder vary by global location.
Pay attention to your routines
The main symptoms to look out for are feeling sad, changes in appetite (eating more) and sleep (wanting to sleep more), not enjoying things the way you used to and feeling hopeless about yourself, the world and the future. There could also be a lack of energy and difficulty getting out of bed in the morning.
Weather or not: Exercise is something we do in warmer months that can fall off in winter, so look at how you can tweak your daily routine to maintain your activities.
Usually these kinds of symptoms take a number of weeks or months to evolve – it's rare that they appear overnight. Most of us know when we're just having a bad day or might be struggling with a cold or flu.
But if symptoms linger and they last more than two weeks, people need to pay attention.
The first step for all of us at this time of year is to take a few minutes to reflect on our daily routines. There are often activities we do during the warmer months that we may not do in winter.
The reality is if we don't continue some habits and routines, we risk losing the joy we get from everyday activities.
Most of us love the outdoors but in the winter months we may fall out of the rhythm of going outside or getting exercise during evening because it's dark and cold.
But the reality is if we don't continue some habits and routines, we risk losing the joy we get from everyday activities.
Adapt your behaviour
What do you normally do during the warmer months? What do you most enjoy doing, and what's harder to do in winter and what can you do about it?
Cold comfort: Keep up your socialising during winter, says Dr Titov, and also be mindful about sleep and diet.
If you usually exercise at night, you may want to go for a walk in the morning or at lunchtime when you can get some sunshine. If you enjoy socialising you might have people come to your home or visit theirs and watch sports together, share hobbies or other interests.
People also need to be mindful about their sleep – healthy sleep patterns are essential. When we lose our usual rhythms during the day, we often change our sleep habits to compensate. We might go to bed later or we might watch shows in bed, which we wouldn't normally do.
This changes our ability to get to sleep and stay asleep, which can have significant effects on our energy levels during the day. Going to bed and getting up at the same times is a great way to keep sleep routines healthy.
Another aspect for attention is nutrition. The temptation, and we all love it, is to have lots of hearty, warm meals at night in winter. It's fine to sometimes have those foods, but if we have too much, it isn't going to help. You will feel stodgy and tired, and start to put on kilos – all of which make it harder to get out and about.
Winter can make it harder to keep up good habits, but we do have a choice about the things we do. Research shows we thrive when we do things we find challenging, rewarding and stimulating.
By paying attention to our habits and routines and tweaking these, not only can we get through winter but we can also enjoy this special time of year.
Dr Nick Titov (pictured) is a Professor in the Department of Psychology and Executive Director of the MindSpot online mental health clinic.
