Seasonal Affective Disorder (SAD)

This content mentions suicide or suicidal thoughts and depression. Please read with care. There are details of where to find help at the bottom of this page.


  • What are the symptoms of SAD?
  • What causes SAD?
  • Getting support
  • Ways you can look after yourself

Many of us are affected by the changing seasons. The colder weather and darker evenings can affect our mood, energy levels, sleeping patterns, and appetites. But if this affects your daily life, you may have Seasonal Affective Disorder (SAD).

SAD can affect you at any time of year, although it’s more common in winter. However, some people have symptoms of SAD in summer and feel better in winter.

What are the symptoms of SAD?

The symptoms of SAD are similar to those of depression. For example, you might:

  • feel sad, tearful or hopeless
  • have no energy
  • feel anxious or worried
  • find it hard to concentrate
  • be unable to enjoy things that usually bring you pleasure
  • lose interest in sex
  • not want to see people
  • feel suicidal

As well as this, you may feel sleepy during the day and find it hard to get up in the morning. Your appetite might change – in particular, people with SAD can crave food high in carbohydrates.

If you have another mental health condition, you may find your symptoms get worse when you’re also affected by SAD.

What causes SAD?

While the exact causes of SAD are unclear, it’s often linked to the reduced amount of sunlight in winter. This can affect:

  • your body clock. Your body uses sunlight to regulate your sleep, appetite and mood. Lower light levels in winter can disrupt your body clock, leading to depression and tiredness
  • your production of melatonin, a sleep hormone. People with SAD may produce much higher levels in winter
  • your production of serotonin, a hormone affecting your sleep, mood and appetite. Reduced sunlight can lead to lower levels of serotonin, making you feel depressed

You’re more likely to develop SAD if you have a relative with SAD or another form of depression. Like other types of depression, SAD is more common in women: they are three times more likely to be affected than men.

Getting support

If you think you have SAD, speak to your doctor. NICE – the organisation that produces guidelines for healthcare professionals – recommends SAD is treated in the same way as depression, through talking therapy and/or medication. This is because there isn’t enough evidence to show other types of treatment help with SAD.

Our page on depression has more information on the treatment you may be offered.

Ways you can look after yourself

It can be difficult to live with SAD, but there are things you can do to help yourself.

  • Light, especially natural light, can greatly affect your overall mood. Spend some time each day outside if you can, and open your curtains to let as much light in as possible. Avoid sitting in dark or dimly lit rooms. Use lamps & mirrors to brighten up anywhere that is particularly dark.
  • Some people find it helpful to use a lightbox – a special lamp that mimics natural light. Talk to your doctor before using one, especially if you have any eye or skin problems.
  • Exercise and spending time in green spaces are helpful for everyone’s mental health. Physical activity can boost your self-esteem and help you concentrate, sleep and feel better.
  • Plan for the difficult times. For example, you could freeze meals if you know you won’t have the energy to cook or make sure you have time to relax or get an early night.
  • Thinking differently about winter may help. Research shows that reframing how we think about stressful events can help us deal much better with them. Think about the things you enjoy about winter: making comfort food, curling up under a blanket, walking through crunchy leaves or visiting Christmas markets, for example.

If you are feeling like ending your life or feel unable to keep yourself safe, please call 999 or go to A&E and ask for the contact of the nearest crisis resolution team. These are teams of mental health care professionals who work with people in severe distress. If you feel affected by the content you have read, please see our get help page for support.

* Last updated: 15 February 2022

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