Seasonal Affective Disorder (SAD): How to Beat it Without a Fight

We all love nature. We pause to admire its variety and its quiet, breathtaking beauty. It reminds us that life does not always have to be complicated, providing us with free moments of calm, pleasure, and freedom in our constant world of rush and demands. At the same time, we instinctively understand how deeply connected we are to it.

Our wellbeing, and even our very existence, depends on nature in ways we often take for granted. We respect its power, too, and the subtle yet profound influence it has on how we feel, think, and live. One of the clearest expressions of this power is the rhythm of the seasons.

Each year, nature gently, but persistently, redefines our environment through its quarterly changes. Each season arrives with its own personality and a distinct set of experiences. Some feel uplifting and energising, others feel heavy or restrictive, and many sit somewhere in between. These shifts are not just background scenery to our lives. They can shape our mood, motivation, and mental health so strongly that, for some people, they contribute to a condition known as Seasonal Affective Disorder, or SAD.

What Is Seasonal Affective Disorder?

Seasonal Affective Disorder (SAD) can be simply defined as:

A type of depression that follows a seasonal pattern.

It appears at the same time each year and affects people who otherwise experience stable mental health for the rest of the year. For most, symptoms begin in the autumn or winter months which is why it is often referred to as winter depression, and gradually ease as spring approaches.

This is not the same as the winter blues. The winter blues are relatively common and may involve feeling a little flatter, more tired, or less motivated during the colder months. However, they tend to be short-lived and do not significantly interfere with daily life. SAD is more severe and can disrupt work, relationships, and overall wellbeing.

A less common form of SAD also exists known as summer depression. Rather than emerging in winter, symptoms begin in early summer and usually resolve by autumn or winter. This form accounts for only around 10% of cases, making it far less frequently seen than winter-related SAD.

Incidence and Risk Factors

SAD affects around 0.5 to 3% of the general population. It is most commonly seen in young adults aged 20 to 30 and tends to affect women more often than men. For many people, SAD does not appear out of nowhere. Certain life circumstances and personal factors can make someone more vulnerable.

Living far north or far south of the equator can increase the risk, as these regions experience greater seasonal changes and long periods with limited sunlight. For some, SAD is also linked to an existing mental health condition, such as depression, which is present in around 10% of cases, or bipolar disorder, which is associated with roughly 25% of cases. A family history of SAD, depression, or other mental health conditions can also play a role, suggesting that genetics and shared environments may influence who is affected.

Signs and Symptoms

SAD shares many symptoms with depression, but with one important difference. These feelings tend to return at the same time each year, often catching people off guard as the seasons change.

You may notice:

• A persistent low mood that stays for weeks

• Losing interest in activities that once brought enjoyment

• Ongoing tiredness or a noticeable drop in energy

• Low self-esteem or harsh self-criticism

• Feelings of hopelessness, guilt, or worthlessness

• Changes in appetite or weight

• Sleep difficulties, whether sleeping too much or too little

• Reduced interest in sex

• Trouble concentrating or staying focused

• Increased irritability or agitation

• Pulling away from friends, family, or social situations

• Thoughts of self-harm or suicide

Alongside these general symptoms, SAD can look slightly different depending on the season in which it appears. Winter-pattern SAD often brings a heavy, slowed down feeling. People may experience:

• Oversleeping and difficulty getting out of bed

• Increased appetite, especially cravings for carbohydrate-rich foods

• Gradual weight gain

Summer-pattern SAD, which is much less common, tends to feel more restless and agitating. Symptoms may include:

• Difficulty sleeping or persistent insomnia

• Reduced appetite and unintentional weight loss

• Heightened anxiety or inner restlessness

• Episodes of anger or aggressive behaviour

What Are the Causes?

SAD is a complex condition and there is no single, clear cause. What research consistently shows, however, is a strong link with reduced exposure to natural daylight during the shorter days of autumn and winter. This effect appears to be particularly significant in people who are already more vulnerable to mood disorders, such as those with a genetic predisposition that makes them more sensitive to seasonal changes. Several theories help explain why SAD develops in some people and not others.

Disruption to circadian rhythm

Our bodies rely on an internal clock to regulate daily patterns such as sleeping, waking, and energy levels. During autumn and winter, shorter daylight hours and longer nights can interfere with this rhythm. Many people with SAD struggle to adjust to these variations, leading to the classical changes in mood and behaviour that can persist throughout the winter months.

Hormonal imbalance

Sunlight plays an important role in supporting the hypothalamus, a small but vital area deep within the brain that helps regulate sleep and alertness. When daylight exposure drops, the hypothalamus may struggle to regulate key hormones effectively. This can disrupt levels of melatonin, serotonin, and dopamine, all of which are closely linked to mood, appetite, motivation, and sleep quality.

Vitamin D deficiency

Reduced sunlight during winter often leads to lower vitamin D levels, as natural daylight is essential for its production in the skin. Vitamin D is involved in regulating serotonin, sometimes referred to as the feel good hormone. When vitamin D levels fall, serotonin regulation may be affected, contributing to low mood, fatigue, and sleep disturbances.

Changes in weather and temperature

Some people are especially sensitive to changes in their external environment, including colder temperatures, darker mornings, and persistent cloud cover. These shifts can subtly but steadily affect mood and daily functioning, making it harder to maintain emotional balance. As a result, SAD is more common in regions with greater seasonal variation and less consistent daylight, such as the UK for example.

Diagnosing SAD

SAD is diagnosed using a clear set of criteria that help distinguish it from other forms of depression.

Symptoms of clinical depression must appear only during certain times of the year, most commonly in the autumn or winter months. These seasonal episodes must follow a consistent pattern, taking place during the same season for at least two consecutive years. Also, depressive episodes linked to a particular season must happen more frequently than depressive episodes at other times throughout a person’s life.

If these symptoms feel familiar, it’s worth remembering that SAD can be treatable. Reaching out to a healthcare provider can help turn that understanding into action, bringing clarity, reassurance, and access to support and treatments that can help you manage your symptoms and start feeling more like yourself again.

How Can it Be Treated?

A wide range of effective treatments is available for SAD, and the best approach is often one that fits comfortably into your daily life, routines, and personal preferences. For many people, small, consistent changes can make a meaningful difference, while others may benefit from a more structured treatment plan. Common treatment options include:

Increasing exposure to natural light

Spending more time outdoors during daylight hours or allowing more natural light into your home or workplace can help lift your mood and regulate the body’s internal clock. Even short daylight breaks can feel refreshing during the darker months.

Exercise

Regular physical activity improves both physical and mental health. Outdoor exercise, in particular, offers the added benefit of daylight exposure. Even when the weather is less inviting, gentle movement such as walking or stretching can boost mood, enhance energy levels, and promote a sense of wellbeing.

Stress management

Managing stress in healthy ways can significantly improve emotional balance. Practices such as meditation, yoga, or simply spending time with friends and family can all help reduce anxiety, improve mood, and create space for mental recovery during tough periods.

Light therapy or phototherapy

Light therapy is an important treatment for SAD. It involves sitting near a lightbox that mimics natural daylight and emits bright artificial light. For best results, sessions usually last 30 to 45 minutes each morning, starting in autumn and continuing through the winter months when daylight is limited.

Light therapy is generally safe, as harmful UV rays are filtered out, but it may not be suitable for everyone, especially those with certain eye or skin conditions or those taking medications that increase light sensitivity.

Cognitive behavioural therapy

Cognitive behavioural therapy, or CBT, is a structured talking therapy that has proven effectiveness for depression and SAD. It focuses on the connection between thoughts, emotions, and behaviours, helping you recognise unhelpful patterns and replace them with healthier coping strategies. Over time, this can lead to improved resilience and emotional wellbeing.

Drug therapy

For persistent or more severe symptoms, anti-depressant medication may be recommended. Selective serotonin reuptake inhibitors, or SSRIs, are usually the first choice due to having relatively less side effects. These medications work by increasing serotonin levels in the brain, which can help improve mood and enhance the effectiveness of other treatments, such as CBT.

Combination therapy

Using two treatment approaches together, such as SSRIs alongside CBT or light therapy, often works better than relying on a single option.

Vitamin D supplementation

Vitamin D supplements, often called the sunshine vitamin, may be beneficial during the darker months, along with nutrients such as vitamins B6 and B12 and omega fatty acids, which are linked to mood and energy regulation.

Healthy diet

A balanced diet rich in whole foods, emphasising variety and quality, supports both body and mind. Limiting processed foods, refined sugars, and high-salt options can help maintain steady energy and support emotional wellbeing year-round.

Finding Happiness in Every Season

The changing seasons and fluctuating weather are part of the rhythm of life. While we cannot control them, we can choose how we respond. Learning to live well through this variability begins with acceptance and with incorporating this awareness into the fabric of our daily lives.

When we take the time to understand our emotions and behaviours, we start to see how deeply our external environment can influence how we feel, often without us even realising it. This allows us to be kinder to ourselves, more intentional in our actions, and better prepared for the emotional shifts that come with each new season.

By equipping ourselves with this understanding, we can move through seasonal transitions with greater confidence and balance. And in doing so, we give ourselves the best chance of choosing happiness, even during the coldest, darkest days.

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