Everything you need to know about Seasonal Affective Disorder (SAD)
03 January 2025
We're all affected by the weather; while bright sunshine tends to lift our mood, few people bounce out of bed with quite the same enthusiasm on a grey, rainy day.
But for some of us, the impact of seasonal changes is a lot greater than simply preferring long July days to short, dark January ones.
In fact, millions of people in the UK find certain seasons so much harder to cope with, that it affects every area of their lives.
And many of them have already been diagnosed Seasonal Affective Disorder (SAD) as a result.
Here's what you need to know about this potentially debilitating condition, which is believed to affect at least one in 20 adults living in the UK today.
What is SAD?
SAD is a specific form of depression linked to seasonal changes. Also known as "winter depression", it often - but not always - flares up during the colder months.
For some people, SAD symptoms are mild and manageable e.g., low mood and energy levels. But for others, they can be much more severe e.g., relentless insomnia and feelings of despair.
Know your numbers
Just over 35% of the UK population finds their moods affected to some degree in the darker autumn and winter months1.
How do I know if I have SAD?
According to the NHS, the main symptoms of SAD include:
- Persistent low mood
- Lack of interest in everyday activities
- Irritability
- Feelings of despair, guilt, and worthlessness
- Low energy levels
- Sleeping more and finding it hard to get up
- Food cravings and weight gain
- Difficulty concentrating
- Decreased sex drive
These are largely the same symptoms experienced by people with other forms of depression. With SAD, however, they come and go with the changing seasons.
Most people with SAD find the winter months more difficult due to the relative lack of light and warmth. However, that's not always the case; some sufferers experience symptoms during the summer.
So, if you notice your symptoms tend to worsen at a certain time of year, it's worth seeing your GP to talk about SAD.
Did you know?
Men are more likely to be diagnosed with SAD than women2.
What can I do to combat SAD symptoms?
Whether you think you have SAD, or you've already been diagnosed with the condition, the good news is that there are plenty of easy ways to lessen the impact SAD symptoms can have on your life.
Things you can do to help improve winter SAD symptoms include:
- Maximising your sunlight exposure - even going out for a short walk or eating your lunch outside can help, as can sitting near a window when you're indoors
- Eating a healthy, balanced diet - filling your freezer with nutritious, home-cooked meals can be handy for when you lack the energy to cook something on a cold winter day
- Increasing your exercise quota - exercise is known to lift serotonin levels and feeling physically healthier makes it easier to live with SAD symptoms too
- Confiding in your friends and family - they can support you more effectively if they understand how seasonal changes make you feel
- Using a sunrise alarm clock, which wakes you up gradually by lighting up your bedroom rather than sounding an alarm
If your SAD symptoms are worse during the summer months, it's a good idea to:
- Stay hydrated by drinking plenty of water
- Avoid going out during the hottest times of the day
- Wear cool, loose clothing to minimise discomfort
- Seek out enjoyable indoor activities such as going to the cinema with friends
Top tip
Whatever season you find difficult, it may help to keep a diary that allows you to better understand what triggers your symptoms and what - if anything - makes them less severe.
How can SAD be treated?
The four main treatments prescribed for people with SAD are:
- Cognitive behavioural therapy (CBT - talking therapy based on the idea that changing the way you approach and react to situations can help you feel better. The aim is to help you manage everyday events and issues in a more positive way.
- Counselling - talking therapy that involves discussing your worries and problems with a trained counsellor. The topics covered can include past experiences as well as how you feel about yourself and others at the time.
- Antidepressants - medication, most commonly selective serotonin reuptake inhibitors (SSRIs) that increase the level of the hormone serotonin in your brain. The aim is to lift your mood, although people generally take a while to feel the effects and may also experience side effects such as anxiety and an upset stomach.
- Light therapy - treatment that involves sitting by a special lamp called a light box, usually for around 30 minutes to an hour each morning. The aim is to simulate the sunlight that's missing during the darker winter months, potentially reducing daytime melatonin levels and helping to stimulate production of serotonin, the "happy hormone".
Did you know?
The National Institute for Health and Care Excellence recommends that SAD be treated in the same way as other, longer-term types of depression.
What causes SAD?
As with many mental health conditions, the exact cause of SAD is not yet fully understood.
However, for those affected by SAD during the winter, a popular theory is that the reduced exposure to sunlight may stop a part of the brain called the hypothalamus working properly.
The potential effects of this include:
- Higher levels of melatonin, the hormone that makes you feel sleepy - usually at night
- Lower levels of serotonin, the hormone that affects your mood and appetite and can cause feelings of depression when you don't have enough of it
- Body clock disruption, caused by reduced light levels that make it harder for your internal clock, also known as your circadian rhythm, to use sunlight to schedule functions such as when you wake up
As SAD seems to run in families, there may also be a genetic element to the condition.
Don't suffer in silence
If you suspect you have SAD, or you're struggling with any kind of depression, make an appointment to see your GP who can carry out a mental health assessment and prescribe a range of treatments based on the results.
If you have a WPA policy, there may be a range of mental health benefits/services that can help (please check your policy literature to confirm what benefits you have).
You can also contact the NHS on 111 or find details of some other support services on our Mental Health Hub.