Seasonal Affective Disorder (SAD)

What is SAD?

Seasonal Affective Disorder (SAD) is a type of seasonal depression that usually occurs during the winter months (sometimes called ‘winter depression’). SAD can also appear in the summer months for some, (albeit less often). It is diagnosed more often in women than men, and more frequently in younger rather than older adults


The symptoms of Seasonal Affective Disorder can include;

  • Persistent low mood most days
  • Irritability
  • Feeling guilty and worthless
  • Lack of energy and feeling sleepy during the day
  • Sleeping for longer than normal, yet finding it hard to get up in the morning
  • Craving carbohydrates and gaining weight
  • Loss of interest in activities you once enjoyed
  • Finding it hard to concentrate
  • Not wanting to see people

What causes Seasonal Affective Disorder?

Although the exact cause of Seasonal Affective Disorder is not fully understood, it is often linked to reduced exposure to sunlight during shorter autumn and winter days. Consequently SAD is more common among people who live in countries where there are greater changes in the weather and daylight hours across the seasons (including England & Wales). Those who live to the far north or south of the equator can also be affected as these countries have decreased sunlight during the winter and longer days during the summer.

Lack of sunlight may affect a part of the brain called the hypothalamus, (which controls mood, appetite and sleep) from working properly, this can result in;

  • Higher than normal levels of melatonin (the hormone that makes us feel sleepy) as your brain produces melatonin when it’s dark to get your body ready for sleep. This is also what happens to animals when they hibernate.
  • Lower than normal levels of serotonin (the hormone that affects mood, appetite, and sleep)


Lack of sunlight can also affect our body’s internal clock. Your body uses sunlight to time various important functions such as waking up, sleeping, appetite/when you should be hungry and your mood. Therefore lower light levels may disrupt your body clock, interfere with sleep routines, and may slow the body clock down leading to tiredness and depression. Furthermore, some of us feel particularly uncomfortable in hotter or colder temperatures which could contribute to developing depression or depression worsening seasonally. Finally, SAD is more likely to occur in those who already have depression or bipolar (worsening in the winter months).

Overcoming Seasonal Affective Disorder

  • If you experience winter SAD, get as much natural sunlight to correct hormone levels and reset the body clock to what it should be. Going for walks, spending time in parks/gardens, or simply sitting near a window are ideal ways to do this.
  • Try ‘Light Therapy’ (called phototherapy). Get a lightbox to simulate exposure to sunlight. Lightboxes give off strong white/blue light, or you can also try an alarm clock that simulates dawn. Unfortunately, the NHS is unable to provide these as there isn’t sufficient, significant evidence that either of these works. However many people find light therapy very helpful. You can purchase these on Amazon, but be sure it is a BLUE LIGHT box as this mimics daylight and tricks the brain, unlike standard lighting which doesn’t have this effect.
  • If you experience summer SAD, drink plenty of water to stay hydrated, look for shade, avoid going out at the hottest times of the day and visit indoor places for example a cinema.
  • Manage your stress levels, reduce pressure on yourself, and use relaxation and mindfulness techniques to look after your wellbeing
  • Look after your mental health in other ways such as getting enough sleep to improve your mood and increase energy levels. Think about your diet, and eat regularly to keep your blood sugar stable which can make a difference to your mood. You should also exercise regularly to boost your mood. Try to avoid drugs and alcohol as in the long run they can make you feel far worse.
  • Look after your personal hygiene. When you’re depressed it’s easy for hygiene not to feel like a priority, but small things like taking a shower and getting dressed can make a big difference to how you feel.
  • Taking part in hobbies you enjoy or socialising with friends is a positive distraction. Albeit you may lack the motivation to do so, committing to some social time, or a hobby regularly can prove very helpful.
  • Speak to your GP to access talking therapies such as CBT or counselling.
  • Contact helplines such as Samaritans if you are struggling.


Living with SAD can be extremely challenging, however, you are not alone. Here at Trauma Research UK, our belief is, ‘it’s not what’s wrong with you, it’s what happened to you’. With this philosophy, we believe that everyone can successfully overcome their mental health issues if given the right help and support. Read more…

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Trauma Research UK’s recovery programme is designed to help you break the anxiety-inducing habits you might have been carrying around for years, and to help you create new ways of thinking that we are confident will transform your life for the better. We will share with you the techniques and tools needed to change things around so you can start to live the life you deserve. This programme has been designed to be simple, effective and most importantly life-changing. Find out more…