Seasonal Affective Disorder, woman sitting by a window with her head in her hands, e-Surgery

The Winter Blues Are A Real Condition

Depression. It’s a term we’re all familiar with, but it comes in many different forms. Depression arises in different people for a variety of reasons, usually from a combination of factors in someone’s life. What kind of factors?

Traumatic or upsetting life events such as bereavement or the breakdown of a relationship can often be reasons for depression, though not every depressive episode is caused by a particular experience that can be identified. It can be the result of living with stress for a long time or overall burnout from work. A depressive phase might even begin without a clear cause. We do know that a family history of depression puts you at a higher risk of developing the condition, as do certain personality types [1].
But what about feeling depressed due to the weather, or seasonal changes? Sure, most of us prefer a sunny day over a wet, rainy one, but can this really cause a condition as serious as depression, or is it all hyperbole? The name of the condition is Seasonal Affective Disorder, aptly known as SAD, and it’s very real – around 29% of the UK population experience it in one form or another [2].

Autumn leaves  on wet pavement | What Is Seasonal Affective Disorder And How Can You Treat It? | e-Surgery

What Is Seasonal Affective Disorder (SAD)?

SAD typically takes the form of a consistent low mood or depression during a particular season, or in response to a kind of weather. For most people, SAD begins as the daylight hours get shorter, the temperature drops and the weather gets worse, so usually late autumn and winter. This is why it can be known as the ‘winter blues’. However, it’s not universal. You could get seasonal depression during the summer months. As long as it’s tied to a seasonal pattern, it’s known as SAD. 

What Causes Seasonal Affective Disorder (SAD)?

The causes of SAD can vary.  One prevailing theory is that the lack of sunlight during wintertime disrupts the ordinary working of our brain ⑶.

Low levels of sunlight could stop the hypothalamus – an important part of our brain – from working properly. If the hypothalamus isn’t working properly, that has a knock on effect on the rest of our brain and body. For example, it can disrupt our production of melatonin, which dictates our sleep patterns. This can make us feel sleepy and fatigued, and generally upset our sleeping patterns. It can also mess with serotonin, a hormone that affects mood, appetite and sleep, as well as our body’s internal clock.

We also know that outdoor exercise [4] and connection to nature [5] are great mood boosters, and winter weather can restrict both of those activities. If these factors cause a low mood that does not dissipate, it can really begin to affect your daily routine and your ability to engage with the world and others around you. 

What Are Some Of The Symptoms Of Seasonal Affective Disorder (SAD)?

Depression presents in many ways, and it’s no different when it comes to SAD. However, there are common symptoms for the condition. If you experience these symptoms on a consistent seasonal basis, you should talk to your doctor about SAD.

Common SAD symptoms include:

• Persistent low mood

• Lack of pleasure and loss of interest in daily activities, known as Anhedonia

• Feelings of fatigue and lethargy

• Disturbed sleeping patterns, ranging from insomnia to sleeping too much 

• Changes in appetite, ranging from cravings to disinterest in food

• Increased irritability

• Feeling without hope, despairing

• Feelings of guilt and low self-worth

As you can see, SAD can manifest in many different ways. So you may have all of, or just some of, the listed symptoms. You may even have symptoms that aren’t listed. It’s important to remember that SAD can co-exist with, and be influenced by, other health conditions both mental and physical.

If SAD becomes severe, it can even lead to suicidal feelings and ideation. If you do experience suicidal feelings from SAD, it’s very important you speak to someone about it and seek medical help, because it’s a very serious health issue that can be a medical emergency. Make sure to check out these Crisis Resources if you or someone you know needs help.

Young girl looking sad leaving over the edge of a sof | What Is Seasonal Affective Disorder And How Can You Treat It? | e-Surgery

How Can I Be Diagnosed With Seasonal Affective Disorder (SAD)?

If you do experience these symptoms, you’ll want to consult a doctor about it. There’s a lot to consider here, as many of the symptoms of SAD can be caused by other health conditions. For example, anaemia could be causing fatigue. You could also be experiencing low mood from a host of other factors, some of which you might not have even considered, such as social media usage and diet.

Diagnosing SAD is about finding a pattern. If periods of depression consistently occur at a certain time of the year, and then your depression goes away once the seasons change, SAD can be confidently diagnosed. There is also the possibility that you have depression throughout the year, but one season in particular makes your condition worse.

How Can Seasonal Affective Disorder (SAD) Be Treated?

As with any treatment, it comes down to individual circumstances and your doctors advice. There are a variety of treatments for SAD, some general and some more specific to the condition.

After your diagnosis, you’ll often be advised to:

• Get as much natural sunlight as you practically can (while remembering sun safety).

• Improve lighting at work and at home.

• Exercise regularly, outside if possible.

These are helpful tips that you can incorporate into your daily routine to reduce the risk of SAD symptoms. However, they can’t always treat the condition entirely. 

Cognitive Behavioural Therapy (CBT) and counselling are often recommended for depression, and that includes SAD. Working through your thoughts and feeling with a therapist can be very helpful, and it’s now available through the NHS [6].

Antidepressants can also be prescribed for severe cases of SAD, although the seasonal nature of the condition means that antidepressants may not always be appropriate. In most SAD cases, antidepressants would be taken at the start of the winter season before symptoms appear, and continued until spring.

Low profile of men running forwards from thighs down on wet pavement | What Is Seasonal Affective Disorder And How Can You Treat It? | e-Surgery

Does Light Therapy Treat Seasonal Affective Disorder (SAD)?

There is some evidence that light therapy can be an effective SAD treatment, although it’s not seen as conclusive [7]

The therapy involves sitting by a ‘light box’, a powerful lamp intended to stimulate sunlight, for around 30 minutes to an hour every day. As most light boxes have UV filters, it’s generally seen as a safe form of treatment, unless you have light sensitivity from a condition or medication. It’s not available through the NHS though, so you’ll need to buy a light box yourself and try it. Light therapy won’t prevent SAD from occurring in future, but it could alleviate symptoms during the winter.


1. Major Depression And Genetics | Stanford Medicine

2. Impact Of Seasonal Affective Disorder Twice As High As Previous Reports | The Weather Channel

3. Abnormal Hypothalamic Response To Light In Seasonal Affective Disorder | PubMed

4. More Evidence That Exercise Can Boost Mood | Harvard Health Publishing

5. Sour Mood Getting You Down? Get Back To Nature | Harvard Health Publishing

6. Cognitive Behavioural Therapy (CBT) | NHS

7. Short Exposure To Light Treatment Improves Depression Scores In Patients With Seasonal Affective Disorder: A Brief Report | PubMed

Further Reading

1. Mental Health Charities And Organisations | NHS

2. Seasonal Affective Disorder (SAD) | Mind

3. Seasonal Depression | WebMD

4. Anaemia | PatientInfo