What is SAD?

Person leaping in front of sun

Seasonal Affective Disorder (SAD) is something that affects most of us to varying degrees and at the same time each year. It is linked to the changing of the seasons and generally will begin as the days get shorter and the weather becomes colder.

People with SAD will feel depressed during the shorter winter days and more cheerful and energetic during the brightness of spring and summer.

So generally this is what we think of as the ‘winter blues’. For most people the symptoms are mild and don’t interfere with day-to-day life too much, but for a small number of people the symptoms can be much more severe to the extent that they will find it hard to carry out everyday tasks.

Women silhouetted against tree durng winter

What are the Symptoms of Seasonal Affective Disorder?


There are many symptoms of SAD, they include:

  • a persistent low mood
  • a lack of interest in normal everyday activities
  • irritability
  • feeling lethargic and sleepy during the day
  • sleeping for longer than normal and finding it hard to get up in the morning
  • craving carbohydrates and gaining weight
  • lack of energy for everyday tasks, such as studying or going to work
  • concentration problems
  • depression – feeling sad, low, tearful, guilty, like you have let others or yourself down;
  • anxiety – tenseness and inability to cope with everyday stresses;
  • panic attacks
  • being more prone to illness – some people with SAD may have a lowered immune system during the winter
  • getting colds, infections and other illnesses
  • loss of interest in sex or physical contact
  • social and relationship problems – irritability or not wanting to see people; difficult or abusive behaviour
  • alcohol or drug abuse.
Tired woman sleeping on sofa

What causes Seasonal Affective Disorder?


The causes of SAD still aren’t fully established, although there are several theories on what causes it and why some people are more susceptible to it than others.

Some people need more light than others

When light hits the back of the eyes messages are passed to the part of the brain that rules sleep, appetite, sex drive, temperature, mood and activity. If there isn’t enough light these functions slow down and stop. Some people seem to need more light than others for their body to function properly and will therefore develop SAD symptoms more easily if there are low levels of light.

Low serotonin levels

Serotonin is the main brain chemical involved in SAD. It is a hormone that affects your mood, appetite and sleep. A lack of sunlight may lead to lower serotonin levels and people suffering from depression have been found to have lower serotonin levels.

High melatonin levels

Melatonin is a hormone that makes us feel sleepy. When it is dark the brain produces melatonin which makes us sleep. When it is light it stops producing melatonin and we wake up.

It has been found that people with SAD produce much higher melatonin levels in the winter, making them want to sleep more. This is also what happens to animals when they hibernate.

Disrupted body clock

Your brain sets your body clock by the hours of daylight – it uses sunlight to time important functions such as when you wake up. A theory is that if the part of the brain doing this doesn’t work properly, your body clock slows down leading to tiredness and depression.

Other factors

SAD can also sometimes be triggered by other unwelcome or traumatic life events, such as deaths or serious illness. It could also be caused by changes to diet and medication or the use of, or withdrawal from, drugs and alcohol.

Sometimes people who have lived near the equator for part of their lives and then moved to an area where the seasons are more marked can be vulnerable to developing SAD.

Man resting head in hands and looking tired

What can you do to help yourself?


There are several things you can try to help you manage SAD. They include:

Get outside during the winter months

Take every opportunity to get into natural light during the winter months. Going out on your lunch break for instance can help reduce SAD symptoms.

Manage your stress levels

Now it is easier said than done to avoid stressful situations completely, but it is a fact people are more likely to suffer from stress in the winter months. Plan ahead and try and arrange stressful events such as changing jobs, decorating the house or moving home for the summer months. Try and make sure you have some spare time to rest and relax during the winter.

Lead a healthy lifestyle

Try to exercise regularly. Even if you don’t feel like it at the time physical activity can be very effective in making you feel better and increasing your energy levels. Something as simple as going for a light walk or doing some gardening can really help.

Also eat well – try taking some vitamin B supplements and have plenty of fruit and vegetables. Avoid that craving for carbs such as pasta and potatoes.

Go on holiday!

If you can afford it a holiday to a sunnier place can make a difference. Although there is also the argument that if you go away on your return it can make SAD symptoms worse, so it is always worth checking with your GP first.

Light therapy

Treatment by light therapy – using a light box – is one of the most effective ways to help with SAD and is recommended by a variety of medical institutions. Light boxes are at least ten times the intensity of household lights and are available in lots of different strengths and sizes.

See the Light Therapy section for more details on this or visit the Choosing a SAD Light section for help choosing a SAD light.

Also check our my reviews:

SAD Light on table by window

Medical treatment


If you cannot manage your symptoms yourself, or that SAD is having a significant impact on your daily life then consult your GP who will recommend the most suitable treatment option for you. This might include:

  • Talking treatments – such as counselling or cognitive behaviour therapy
  • Anti-depressants – Anti-depressant drugs work by lifting your mood and helping you cope with the symptoms.
  • Herbal remedies – sometimes St John’s Wort, a herbal remedy is used to deal with mild or moderate symptoms of SAD. It isn’t suitable if you are using a lightbox though as it can make your skin very sensitive to light.

As in all cases consult your GP before undertaking any medical treatment.