At this time of year, as the nights draw in, some people experience a drop in mood, reduced enjoyment of activities that they usually enjoy engaging in, and perhaps a sense of lethargy and sleepiness in the daytime. Their sleep may also be affected, either needing a longer sleep duration or more difficulties sleeping, giving rise to insomnia in some cases. Coupled with this, they might also experience cravings for sugary foods, and gain weight.

There is a link between how far away from the equator somewhere is, and the prevalence of SAD there. The further north or south of the equator you are, the higher the chance of being affected. It is believed that this is related to how much day length is shortened in winter. As days shorten, there is less chance of light exposure during the average day. Winters are also likely to be colder, limiting opportunities to engage in some activities and making it more tempting to plump for a​ duvet day​. It can also mean that working standard hours means that none of your free time on weekdays is spent in daylight, an effect that can be compounded by working in buildings that do not let in much natural light.

Melatonin, the hormone that brings about sleepiness when light levels dim, ideally drops to very low levels in the day as a result of light exposure, and then gradually increases in the evening but the contrast between day and night is less extreme in the winter, and we might use more artificial lighting or screen-based media, meaning that the levels do not rise as they might naturally in the evening. The body clock has less information available to help it synchronise to day and night, and thus sleep-wake times can start to drift. We might also spend more time in bed but not asleep, eroding the clear relationship between bed and sleep, and confusing our mind and body about what it is supposed to do when we are in bed. As sleep quality suffers, we might reach the morning feeling less refreshed, and find it harder to get up, exacerbating the sleep difficulties and making bed an unpleasant place to be.

All of these factors can interact to make us feel worse during the winter. I experienced this first-hand when I lived in Aomori, Japan, which is by some metrics the snowiest place on earth. Winters were cold, dark and arduous, and whilst there was plenty to do, it was easy to get bogged down in the cold and when injuries were added to the mix, I found my mood could suffer.

Fortunately, there are lots of things that can be done to fight the winter blues. The NICE Guidelines are based on the ones for depression, but it is important to take the seasonal variability of the condition into consideration. Some improvement in our sleep quality can be achieved with a few straightforward measures. Making sure we get at least 20 minutes exposure to daylight (ideally) or a SAD lamp in the morning as soon as possible after getting up helps to cue us into wakefulness, eradicates melatonin in our system and helps keep the body-clock synchronised to appropriate wake-sleep timings. It is best to do this out of bed, so whilst an alarm with light might help us to wake initially, it is important to aim to get out of bed as soon as possible after waking.

It can be tempting to go to bed earlier, and ​try​ to sleep, but if we are not sleepy-tired (as opposed to physically fatigued) this can be unhelpful as we are unlikely to sleep, and will

probably simply end up more frustrated. Thus only going to bed when sleepy-tired is the best policy. It is best to aim to avoid all screen-based media for at least the hour before bedtime, and use red-shifting software such as ​f.lux​ on all devices where possible. Charging smart devices outside the bedroom can also eliminate the temptation to enter the whirlpool of a nocturnal social media check-in. If significant difficulties with sleep develop, it could be helpful to see a therapist who can conduct a through assessment and deliver treatment including CBT for Insomnia.

When we feel low, our activity levels can decrease, and this can become a vicious cycle as our lowered activity levels make us feel even lower. It can be tempting when in this situation to plan to wait until we feel motivated to engage in activities, but sometimes the motivation arises at the wrong times, or sometimes we don’t reach the point when we feel motivated. It can be helpful to make a plan in order to organise and gradually increase activities, aiming for a balance of routine, necessary and pleasurable activities. This approach is known as behavioural activation, and ​here is a video I made describing how to do it​. Activities that can help us feel better include physical exercise, mindfulness, socialising and talking to people about how we feel.

Past difficult experiences that took place in the winter can also feed into SAD. Since it can be related to things in various areas of our lives, and treatment can take place in various ways, it can be helpful to see a therapist who can help to break down the causes and formulate what might be maintaining the situation, as well as work with you in order to try out management strategies and find out what is most effective for you.

If the low mood becomes so severe that it leads to thinking about or actually harming yourself or contemplating suicide, it is important to speak to your GP or if that is not possible, to go to your nearest A&E department for support.

Links

Mind –

https://www.mind.org.uk/information-support/types-of-mental-health-problems/seasonal-affec tive-disorder-sad/
NHS Information about SAD – http://​https://www.nhs.uk/conditions/seasonal-affective-disorder-sad/ ​

NHS Information on Exercise for Depression – https://www.nhs.uk/conditions/stress-anxiety-depression/exercise-for-depression/

SAD Association –
Nice Clinical Guideline for depression – https://www.nice.org.uk/guidance/cg90​
A video I made about behavioural activation – https://vimeo.com/45428288
Sleepio – free to Londoners – ​http://​https://www.good-thinking.uk/resources/sleepio-london/

• It is important to note that some people experience a summer variant of SAD in which the July and August are the most difficult months. This blogpost relates primarily to the winter variant.