Seasonal affective disorder (SAD) is a type of depression that comes and goes in a seasonal pattern. SAD is sometimes known as “winter depression” because the symptoms are usually more apparent and more severe during the winter. Some people with SAD may have symptoms during the summer and feel better during the winter (1).
Symptoms of SAD
Symptoms of SAD can include:
- A persistent low mood
- A loss of pleasure or interest in normal everyday activities
- Irritability
- Feelings of despair, guilt and worthlessness
- Feeling lethargic (lacking in energy) 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
- Difficulty concentrating
- Decreased sex drive
For some people, these symptoms can be severe and have a significant impact on their day-to-day activities (1).
What causes SAD?
The exact cause of SAD is not fully understood, but it’s often linked to reduced exposure to sunlight during the shorter autumn and winter days. The main theory is that a lack of sunlight might stop a part of the brain called the hypothalamus working properly, which may affect:
- Production of melatonin – melatonin is a hormone that makes you feel sleepy; in people with SAD, the body may produce it in higher than normal levels
- Production of serotonin – serotonin is a hormone that affects your mood, appetite and sleep; a lack of sunlight may lead to lower serotonin levels, which is linked to feelings of depression
- Body’s internal clock (circadian rhythm) – your body uses sunlight to time various important functions, such as when you wake up, so lower light levels during the winter may disrupt your body clock and lead to symptoms of SAD
It’s also possible that some people are more vulnerable to SAD as a result of their genes, as some cases appear to run in families (2).
Treatments for SAD
A range of treatments are available for SAD. The GP will recommend the most suitable treatment programme for you.
The main treatments are:
- Lifestyle measures – including getting as much natural sunlight as possible, exercising regularly and managing your stress levels
- Light therapy – where a special lamp called a light box is used to simulate exposure to sunlight
- Talking therapies – such as cognitive behavioural therapy (CBT) or counselling
- Antidepressant medicine – such as selective serotonin reuptake inhibitors (SSRIs)
- TMS (Transcranial Magnetic Stimulation) – medication-free and non-invasive treatment
It’s thought the winter blues, or seasonal affective disorder (SAD), affects around 2 million people in the UK and more than 12 million people across northern Europe. It can affect people of any age, including children (3).
Key symptoms:
- Depression
- Sleep problems
- Lethargy
- Overeating
- Irritability
- Feeling down and unsociable
According to Sue Pavlovich of the Seasonal Affective Disorder Association (SADA), these 10 tips could help. “Everyone’s affected differently by SAD, so what works for one person won’t for another,” she says. “But there’s usually something that will help, so don’t give up if the first remedy you try doesn’t work. Just keep trying.”
1. Keep active
Research has shown that a daily one-hour walk in the middle of the day could be as helpful as light treatment for coping with the winter blues.
2. Get outside
Go outdoors in natural daylight as much as possible, especially at midday and on brighter days. Inside your home, choose pale colours that reflect light from outside, and sit near windows whenever you can.
3. Keep warm
If your symptoms are so bad that you can’t live a normal life, see your GP for medical help. Being cold makes you more depressed. It’s also been shown that staying warm can reduce the winter blues by half.
Keep warm with hot drinks and hot food. Wear warm clothes and shoes, and aim to keep your home between 18C and 21C (or 64F and 70F degrees).
4. Eat healthily
A healthy diet will boost your mood, give you more energy and stop you putting on weight over winter. Balance your craving for carbohydrates, such as pasta and potatoes, with plenty of fresh fruit and vegetables.
5. See the light
Some people find light therapy effective for seasonal depression. One way to get light therapy at home in winter is to sit in front of a light box for up to two hours a day.
Light boxes give out very bright light at least 10 times stronger than ordinary home and office lighting. They’re not available on the NHS and cost around £100 or more.
“Some people find that using a dawn simulator [a bedside light, connected to an alarm clock, that mimics a sunrise and wakes you up gradually] as well as a light box can enhance the beneficial effect,” says Pavlovich.
6. Take up a new hobby
Keeping your mind active with a new interest seems to ward off symptoms of SAD, says Pavlovich. “It could be anything, such as playing bridge, singing, knitting, joining a gym, keeping a journal, or writing a blog. The important thing is that you have something to look forward to and concentrate on,” she adds.
7. See your friends and family
It’s been shown that socialising is good for your mental health and helps ward off the winter blues. Make an effort to keep in touch with people you care about and accept any invitations you get to social events, even if you only go for a little while.
8. Talk it through
Talking treatments such as counselling, psychotherapy or cognitive behavioural therapy (CBT) can help you cope with symptoms. See your GP for information on what’s available locally on the NHS and privately, or read this article on how to access talking treatments.
9. Join a support group
Think about joining a support group. Sharing your experience with others who know what it’s like to have SAD is very therapeutic and can make your symptoms more bearable.
SADA is the UK’s only registered charity dedicated to SAD. It costs £20 (£10 for concessions) to join, and you’ll receive an information pack, regular newsletters, discounts on products such as light boxes, and contacts for telephone support.
10. Seek help
If your symptoms are so bad that you can’t live a normal life, see your GP for medical help (3).
Treatment
Seasonal affective disorder (SAD) can usually be successfully treated using various treatments, such as cognitive behavioural therapy, antidepressants and light therapy.
Depending on the nature and severity of your symptoms, your GP will recommend the most suitable treatment option for you. This may involve using a combination of treatments to get the best results.
NICE recommendations
The National Institute for Clinical Excellence (NICE) recommends that SAD should be treated in the same way as other types of depression.
This includes using talking treatments, such as cognitive behavioural therapy (CBT) or medication, such as antidepressants (see below).
Light therapy is also a popular treatment for SAD. There is no strong evidence to support the long-term benefits of using light therapy to treat SAD, although research does suggest that it may have a positive short-term effect.
See the NICE guidance about the treatment and management of depression in adults (4).
Cognitive behavioural therapy
Cognitive behavioural therapy (CBT) starts with the idea that your problems are often created by you. It is not the situation itself that is making you unhappy, but how you think about it and how you react to it.
Changing how you think about certain situations will help you change your behaviour so that the situation no longer makes you feel unhappy.
CBT involves having a number of sessions with a specially trained therapist, usually over several weeks or months. Your programme could be:
- An individual programme of self-help
- A programme designed for you and your partner (if your depression is affecting your relationship)
- A group programme that you complete with other people who are in a similar situation
- A computer-based CBT programme that is tailored to your needs and supported by a trained therapist
- Counselling and psychodynamic psychotherapy
- Counselling is another type of talking therapy that involves talking to a trained counsellor about your worries and problems.
During psychodynamic psychotherapy, you discuss how you feel about yourself and others and you talk about experiences in your past.
The aim of the sessions is to find out whether anything in your past is affecting how you feel today.
Antidepressants
Antidepressants are often prescribed to treat depression and they are also sometimes used to treat SAD when the symptoms are severe.
Selective serotonin reuptake inhibitors (SSRIs) are the preferred type of antidepressants for treating SAD. They increase the level of the hormone serotonin in your brain which helps to lift your mood.
If you are prescribed antidepressants, be aware that:
- It can take between four-to-six weeks for the medication to take full effect.
- It is important to take the medication as prescribed and to continue taking it even if you start to feel better.
- Some antidepressants have side effects and may interact with other types of medication that you are taking.
- An upset stomach is the most common side effect of antidepressants. See the information leaflet that comes with your medication for a full list of possible side effects.
The evidence that antidepressants are effective in treating SAD is limited. They are thought to be most effective if they are taken at the start of winter (before the symptoms appear) and continued until spring.
Light therapy
For some people with SAD, using light therapy can help improve their mood considerably. It involves sitting in front of, or beneath, a light box.
Light boxes are special lamps that come in a variety of designs, including desk lamps and wall-mounted fixtures. They produce a very bright light. Light intensity is measured in lux – the higher lux, the brighter the light.
Before using a light box to treat SAD, check the manufacturer’s information and instructions regarding:
- Whether the product is suitable for treating SAD
- The light intensity you should be using
- How long you need to sit in front of the light
When buying a light box, make sure that you choose one that has been produced by a fully certified manufacturer and is medically proven to treat SAD. The SAD Association (www.sada.org.uk) can provide a list of recommended manufacturers.
Very bright light may not be suitable if you:
- Have an eye problem or your eyes are particularly sensitive to light
- Are taking certain types of medication, such as antidepressants
- Have epilepsy – a condition that causes seizures (fits)
Speak to your GP if you unsure about the suitability of a particular product.
How light therapy works
Light therapy is thought to work by simulating the sunlight that is missing during the darker winter months.
The additional light encourages your brain to reduce the production of melatonin (the hormone that makes you sleepy) and increase the production of serotonin (the hormone that affects your mood).
Altering the levels of melatonin and serotonin that are released into your body during the winter months can help to ease your symptoms of SAD.
However, this is based on the assumption that the condition is caused by a lack of light and the effect that this has on the hormones that are released in your brain.
Research into light therapy
There is mixed evidence regarding the overall effectiveness of light therapy. It is difficult to compare the research that has been carried out in this area because a variety of light sources were used and clinical trials (medical tests) were often conducted over short periods of time.
However, several studies have concluded that light therapy is effective, particularly if it is used first thing in the morning. It is thought that light therapy is best for producing short-term results. This may mean that it will help to relieve your symptoms but that you will still be affected by SAD next winter (4).
Side effects of light therapy
It is rare for people using light therapy to have side effects. However, in rare cases, you may experience:
- Mild agitation or irritability
- Headache
- Sleeping problems (avoid using light therapy during late evening)
TMS Treatment
Repetitive Transcranial Magnetic Stimulation (rTMS) can be administered on an outpatient basis without the need for anaesthesia. This involves applying a specialised electromagnetic coil to the scalp, aiming to generate electric currents in the cerebral cortex. Typically, this treatment is considered for patients with depression that hasn’t responded to antidepressant medication or those for whom antidepressants are not suitable.
In the case of rTMS, repetitive pulses of electromagnetic energy are delivered at varying frequencies or stimulus intensities. Conventional rTMS involves repeating individual pulses at predetermined intervals (a train of pulses), while theta-burst rTMS entails repeating short bursts of pulses at a pre-set interval (a train of bursts). Stimulation can be unilateral, targeting either the left or right dorsolateral prefrontal cortex, or bilateral, involving both cortices either sequentially or simultaneously. A typical rTMS treatment consists of daily sessions lasting around 30 minutes, generally spanning 2 to 6 weeks.
Here at Smart TMS, typically, a series of TMS sessions for Seasonal Affective Disorder (SAD) comprises 30 treatment sessions spread across three to six weeks. Each session, lasting 30 minutes, allows some patients the option of undergoing more than one session in a day.
Nikki, Birmingham Practitioner
References
- Seo, H. (2023). What to Know About Seasonal Depression. The New York Times. [online] 3 Nov. Available at: https://www.nytimes.com/article/seasonal-depression-what-to-know.html.
- Mayo Clinic (2021). Seasonal affective disorder (SAD) – Symptoms and causes. [online] Mayo Clinic. Available at: https://www.mayoclinic.org/diseases-conditions/seasonal-affective-disorder/symptoms-causes/syc-20364651.
- www.lawtonhousesurgery.nhs.uk. (n.d.). Winter Health – Beat the Blues – Lawton House Surgery. [online] Available at: https://www.lawtonhousesurgery.nhs.uk/winter-health—beat-the-blues [Accessed 19 Dec. 2023].
- National Institute for Health and Care Excellence (2022). Overview | Depression in adults: treatment and management | Guidance | NICE. [online] www.nice.org.uk. Available at: https://www.nice.org.uk/guidance/ng222.