Seasonal affective disorder (SAD)

Symptoms of SAD

The symptoms of seasonal affective disorder (SAD) are similar to those of normal depression, but they occur repetitively at a particular time of year.

They usually start in the autumn or winter and improve in the spring.

The nature and severity of SAD varies from person to person. Some people just find the condition a bit irritating. Others can find it severe and to have a significant impact on their day-to-day life.

Depression

Most people with SAD will feel depressed during the autumn and winter.

Signs that you may be depressed include:

• continuous low mood or sadness
• feeling hopeless and helpless
• having low self-esteem 
• feeling tearful
• feeling guilt-ridden
• feeling irritable and intolerant of others 
• having no motivation or interest in things
• finding it difficult to make decisions
• not getting any enjoyment out of life
• feeling anxious or worried 
• having suicidal thoughts or thoughts of harming yourself

Some people experience these symptoms in phases separated by "manic" periods where they feel happy, energetic and more sociable. Further information on depression is available.

As well as symptoms of depression, you may also:

• be less active than normal
• feel lethargic (lacking in energy) and sleepy during the day
• sleep for longer than normal and find it hard to get up in the morning
• find it difficult to concentrate
• have an increased appetite – some people have a particular craving for foods containing lots of carbohydrates and end up gaining weight as a result

These symptoms may make everyday activities increasingly difficult.

When to see your GP

You should consider seeing your GP if you think you might have SAD and you're struggling to cope.

Your GP can carry out an assessment to check your mental health. They may ask you about the following:

• your mood
• lifestyle
• eating habits
• sleeping patterns
• seasonal changes in your thoughts and behaviour

Your GP may carry out a psychological assessment to check your mental health. They may ask about:

• your mood
• your lifestyle
• your eating and sleeping patterns
• any seasonal changes in your thoughts and behaviour
• whether your symptoms prevent you from carrying out normal activities
• whether there's anything in your personal history that may contribute to a depressive disorder, such as child abuse
• whether there's anything in your family history that may contribute to a depressive disorder, such as a family history of depression

Your GP may also carry out a brief physical examination.

Confirming a diagnosis of SAD

SAD can be difficult to diagnose. There are many other types of depression that have similar symptoms. It may take several years before you and your GP realise that your symptoms form a regular pattern.

A diagnosis of SAD can usually be confirmed if:

• your depression occurs at a similar time each year
• the periods of depression are followed by periods without depression
• you've had symptoms during the same time of year for two or more years in a row

Causes of SAD

The exact cause of SAD isn't fully understood.  It’s often linked to reduced exposure to sunlight during the shorter autumn and winter days.

The theory is that a lack of sunlight stops a part of the brain called the hypothalamus working properly.

Certain people may be more vulnerable to SAD as a result of their genes, as some cases appear to run in families.

Treatments for SAD

A range of treatments are available for SAD. Your GP will recommend the most suitable treatment programme for you.

The main treatments include:

• lifestyle measures – including getting as much natural sunlight as possible, exercising regularly and managing your stress levels
• light therapy – using a special lamp called a light box to simulate exposure to sunlight
• talking therapies – such as cognitive behavioural therapy (CBT) or counselling 
• antidepressant medication 

Things you can try yourself

There are a number of simple things you can try that may help improve your symptoms, including:

• try to get as much natural sunlight as possible
• make your work and home environments as light and airy as possible
• sit near windows when you're indoors
• take plenty of regular exercise, particularly outdoors and in daylight
• eat a healthy, balanced diet
• if possible, avoid stressful situations and take steps to manage stress

It can be helpful to talk to your family and friends about SAD so they understand how your mood changes during the winter. This can help them to support you more effectively.

• Find out more about seasonal affective disorder on the NHS website

More useful links

• How to use your health services
• Lifeline
• Mental health emergency - if you're in crisis or despair
• Mental health services
• Mental health support
• Minding Your Head