Seasonal affective disorder (SAD)

Last updated:

Reviewed by:

Dr Rhianna McClymont

, Lead GP at Livi

Medically reviewed

People with seasonal affective disorder (SAD) feel depressed at specific times of the year. We explain the symptoms and what can help.

What is SAD?

Seasonal affective disorder (SAD) is a form of depression that you get during specific seasons or times of the year, or due to certain types of weather. The symptoms only affect you at these times and then go for the rest of the year.

SAD is sometimes called ‘winter depression’ because you commonly experience it during the colder months. But it’s possible to get it during the summer and then feel better in the winter, too.

What causes SAD?

The exact cause of SAD isn’t fully known, but many of the things that can contribute to causing depression can also be a factor with SAD.

Other causes that are specific to SAD might include:

  • How you’re affected by light – We all need light to help our brain control things like sleep, activity, appetite, and mood. But when you need more (or occasionally less) light than others, it can affect mood and energy levels at certain times of the year.

  • Your body’s internal ‘clock’ – Also called our circadian rhythm, is set by daylight hours and helps control functions like when we wake up. During the winter, lower light levels can affect your body clock, leading to SAD.

  • Your hormone levels – A drop in sunlight can lead to lower serotonin levels, a hormone that affects mood, sleep, and appetite. Some people with SAD have higher melatonin levels (the hormone that helps us sleep) in winter. This is similar to animals going into hibernation.

SAD symptoms

Many people find their moods and energy levels change according to the season or the weather. With SAD, these feelings keep coming back at certain times of the year and are so persistent that they affect your day-to-day life.

Common symptoms of SAD include:

  • Feeling persistently low and sad

  • Difficulty concentrating

  • Low energy

  • Sleep problems

  • Feelings of despair and hopelessness

  • In severe cases, suicidal feelings

SAD diagnosis

The first step is to talk things through with a doctor. They will ask you about your moods and emotions, how well you eat and sleep and how these affect your daily life.

To get a SAD diagnosis, a doctor will need to see a seasonal pattern to your symptoms for two years or more. It can be useful to write down some notes about your symptoms and when they happen before seeing the doctor to help you feel more prepared.

SAD treatment

There are various treatments for SAD, and you may need to try different things or a combination of treatments to find what works for you. These might include:

  • Talking therapies – Common therapies are counselling and cognitive behavioural therapy (CBT), which teaches you coping strategies for different situations

  • Medication – A common type of antidepressant, called selective serotonin reuptake inhibitors (SSRIs), is often recommended

  • Light therapy – Some people find it helps to use a lightbox that simulates daylight or dawn, although this isn’t available through the NHS

  • Support services – It can be positive to talk to others who understand how you feel. This may be a local support group or a helpline service run by a charity. Talk to your doctor about what’s available in your area

  • Other treatments – Certain therapies like art and creative therapy and alternative therapies can also be helpful

Lifestyle changes and self-care

There are lots of measures you can take yourself to improve your SAD symptoms. These are very personal to everyone – what works for someone else might not help you – but finding some coping strategies of your own is a good way to feel more in control.

Here are a few things you could try:

  • Keep a diary – Note down your symptoms, and when they happen so you can recognise triggers and times

  • Relaxation techniques – Breathing exercises, meditation and mindfulness, can all help with relaxation and reduce stress

  • Get outdoors – Many people find it helps to spend more time in green spaces and be surrounded by nature

  • Be active – Regular physical activity is a great way to boost your mood and increase your energy levels

  • Eat a healthy, balanced diet

  • Try to follow a regular sleep pattern

Last updated:
Reviewed by:
Lead GP at Livi Dr Rhianna McClymont
Dr Rhianna McClymont, Lead GP at Livi