How Seasonal Affective Disorder (SAD) Affects Mental Health

As the days grow shorter and the skies over Brighton and Hove turn grey, many people notice changes in their mood and energy levels. For some, these shifts go beyond the typical winter blues and develop into seasonal affective disorder (SAD), a recognised form of depression that can significantly impact mental health and daily functioning.

At Brighton Therapy Clinic, we understand how challenging it can be to recognise when seasonal mood changes have become something more serious. In this article, we’ll explore how seasonal affective disorder affects mental health, what causes it, and the evidence-based treatments that can help you feel more like yourself again.

What is Seasonal Affective Disorder?

Seasonal affective disorder, also known as major depressive disorder with a seasonal pattern, is a type of depression that follows a seasonal pattern. Most commonly, people experience symptoms during the autumn and winter months when daylight hours are reduced, though some individuals develop summer-onset SAD.

According to the NHS, SAD is more than simply feeling a bit down when the weather turns cold. It’s a clinically significant form of depression that recurs at the same time each year and can have a profound effect on your emotional wellbeing, relationships, and ability to function in daily life.

The condition affects approximately 5% of adults in the UK, with symptoms typically beginning in late autumn or early winter and improving during the spring and summer months. Understanding how SAD affects mental health is the first step towards seeking appropriate support and treatment.

How Seasonal Affective Disorder Impacts Mental Health

Seasonal affective disorder doesn’t just make you feel sad. It affects multiple aspects of mental health and can interfere with your ability to work, maintain relationships, and enjoy activities you usually find pleasurable. The impact on mental wellbeing can be substantial and shouldn’t be dismissed as simply “winter blues”.

Mood and Emotional Wellbeing

The most obvious way SAD affects mental health is through persistent low mood. People with winter-onset seasonal depression often describe feeling hopeless, worthless, or experiencing a pervasive sense of sadness that doesn’t lift. Unlike temporary sadness, these feelings persist throughout the day and continue for weeks or months.

Many people also experience anhedonia, which is the loss of interest or pleasure in activities they once enjoyed. Social events, hobbies, and even spending time with loved ones can feel like overwhelming tasks rather than sources of joy.

Energy Levels and Physical Symptoms

Seasonal affective disorder often causes significant fatigue and low energy, making even simple tasks feel exhausting. This isn’t ordinary tiredness that improves with rest. Instead, it’s a persistent lethargy that affects your ability to function normally.

Hypersomnia, or excessive sleeping, is common with winter-onset SAD. You might find yourself sleeping much longer than usual yet still feeling unrefreshed upon waking. Some people also experience changes in appetite, particularly cravings for carbohydrates, which can lead to weight gain and further impact self-esteem.

Cognitive Function

SAD can significantly affect your ability to think clearly and concentrate. Many people report difficulty focusing at work, making decisions, or remembering information. This cognitive fog can be particularly distressing for those whose jobs require mental clarity and can contribute to decreased performance and increased stress.

Social Withdrawal and Isolation

The combination of low mood, fatigue, and reduced motivation often leads to social isolation. People with seasonal depression may withdraw from friends and family, cancel plans, or avoid social situations altogether. This isolation can create a vicious cycle, as reduced social contact often worsens depressive symptoms and compounds the impact on mental health.

At Brighton Therapy Clinic, we see how this withdrawal affects not just individuals but also their relationships and support networks.

What Causes Seasonal Affective Disorder?

Understanding the biological mechanisms behind SAD helps explain why it’s a genuine mental health condition rather than simply a lack of willpower or resilience. Several interconnected factors contribute to seasonal depression.

Disrupted Circadian Rhythm

Your circadian rhythm is your body’s internal clock that regulates sleep-wake cycles, hormone production, and mood. Reduced sunlight exposure during winter months can disrupt this rhythm, leading to feelings of depression and fatigue.

The shorter days and longer nights in autumn and winter mean less exposure to natural light, particularly here in the UK where overcast skies are common. This reduction in light exposure can throw off your body’s natural timing, affecting when you feel alert and when you feel tired.

Serotonin and Melatonin Imbalance

Research has shown that reduced sunlight can decrease serotonin levels in the brain. Serotonin is a neurotransmitter that plays a crucial role in regulating mood, and lower levels are associated with depression.

Additionally, the lack of sunlight can cause an overproduction of melatonin, the hormone that regulates sleep. Higher melatonin levels can increase feelings of sluggishness and drowsiness, contributing to the fatigue and hypersomnia characteristic of winter SAD.

Vitamin D Deficiency

Vitamin D, often called the “sunshine vitamin”, is produced in your skin in response to sunlight exposure. During winter months, particularly in northern latitudes, many people develop vitamin D deficiency. Studies have indicated that low vitamin D levels may play a role in depression and possibly other mental health conditions.

While vitamin D deficiency alone doesn’t cause SAD, it may be one contributing factor that, combined with other biological mechanisms, increases susceptibility to seasonal depression.

Recognising the Symptoms of Seasonal Depression

Early recognition of SAD symptoms is important for seeking timely support. While everyone’s experience is unique, common symptoms of winter-onset seasonal affective disorder include:

Persistent low mood or sadness that lasts most of the day, nearly every day. Loss of interest in activities you usually enjoy, including hobbies, social activities, or intimacy. Feeling sluggish, lethargic, or having significantly reduced energy levels. Sleeping much more than usual, including difficulty getting out of bed in the morning. Craving carbohydrates and comfort foods, often leading to weight gain. Difficulty concentrating, making decisions, or thinking clearly. Feelings of hopelessness, worthlessness, or guilt. Irritability or increased sensitivity to rejection. In severe cases, thoughts of self-harm or suicide.

It’s worth noting that summer-onset SAD, though less common, presents differently. Summer SAD symptoms may include insomnia, decreased appetite and weight loss, agitation or anxiety, and increased restlessness.

If you’re experiencing several of these symptoms and they’re affecting your ability to function normally, it’s important to seek professional support. We offer a free initial consultation with a senior practitioner who can help assess your needs and match you to appropriate support.

Risk Factors for Seasonal Affective Disorder

Certain factors can increase your likelihood of developing SAD. Understanding these risk factors can help you recognise if you’re particularly vulnerable to seasonal mood changes.

Living at higher latitudes, where winter days are significantly shorter, increases SAD risk. Here in Brighton and Hove, whilst we’re fortunate to be on the south coast, we still experience considerable reduction in daylight hours during winter months.

Having a personal or family history of depression or bipolar disorder increases susceptibility to seasonal depression. In fact, people with bipolar disorder may be particularly vulnerable to seasonal mood episodes and should monitor for changes in mood patterns.

Women are diagnosed with SAD more frequently than men, though this may partly reflect differences in help-seeking behaviour. Younger adults also appear to be at higher risk, with SAD often first appearing between the ages of 18 and 30.

How Seasonal Affective Disorder is Diagnosed

Proper diagnosis of SAD involves more than simply noticing you feel worse in winter. Healthcare professionals use specific criteria to distinguish seasonal affective disorder from other forms of depression.

According to the diagnostic criteria, to be diagnosed with SAD, you must meet the full criteria for major depression that coincides with specific seasons for at least two consecutive years. Importantly, these seasonal depressive episodes must be more frequent than any non-seasonal depressive episodes you experience.

During an assessment, a healthcare professional or therapist will ask about your symptoms, their timing and duration, and how they affect your daily life. They may also consider your personal and family history of mental health conditions and rule out other explanations for your symptoms.

If you’re concerned about seasonal depression, our team can provide a thorough assessment and help you understand what you’re experiencing. We take a personalised approach, recognising that everyone’s mental health journey is unique.

Effective Treatments for Seasonal Affective Disorder

The good news is that seasonal affective disorder is highly treatable. Various evidence-based approaches can significantly reduce symptoms and improve quality of life during winter months.

Light Therapy

Light therapy, also called phototherapy, is often the first-line treatment for winter-onset SAD. This involves sitting near a special light box that emits bright light (typically 10,000 lux) for about 20 to 30 minutes each morning.

Research indicates that light therapy can be effective for 40% to 60% of people with SAD. The bright light helps reset your circadian rhythm and may boost serotonin levels, improving mood and energy.

Light therapy is generally safe when used correctly, though it’s worth discussing with a healthcare professional before starting, particularly if you have eye conditions or take medications that increase light sensitivity.

Psychotherapy

Cognitive behavioural therapy (CBT) has been specifically adapted for seasonal affective disorder and shows excellent results. CBT for SAD helps you identify and change negative thought patterns and behaviours that worsen depression whilst developing coping strategies for managing symptoms.

Therapy can be highly effective for seasonal depression, offering not just symptom relief but also tools for preventing future episodes. We offer various therapeutic approaches tailored to individual needs, ensuring you receive the most appropriate support for your situation.

Working on breaking negative thinking patterns can be particularly valuable for those experiencing seasonal depression, as it addresses both the immediate symptoms and the underlying thought processes that maintain low mood.

Medication

For some people, antidepressant medication may be appropriate, particularly if symptoms are severe or haven’t responded to other treatments. Selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed for SAD and work by increasing serotonin levels in the brain.

Some healthcare providers may recommend starting antidepressants before the typical onset of symptoms as a preventative measure, then continuing through the winter months. Any decision about medication should be made in consultation with a qualified medical professional who can assess your individual circumstances.

If vitamin D deficiency is identified through blood tests, supplementation may be recommended as part of your treatment plan, though this alone is unlikely to resolve SAD.

Lifestyle Modifications and Self-Care

Whilst professional treatment is important, several lifestyle strategies can support your mental health during darker months:

Maximise exposure to natural daylight by spending time outdoors during daylight hours, particularly in the morning. Even on overcast days, natural outdoor light is beneficial. Here in Brighton and Hove, a walk along the seafront or through one of our lovely parks can provide valuable light exposure.

Maintain regular sleep patterns by going to bed and waking at consistent times, even on weekends. Good sleep hygiene supports your circadian rhythm and overall mental health.

Regular physical activity has well-documented benefits for depression. Exercise releases endorphins and can improve mood, energy levels, and sleep quality. Even moderate activities like walking, swimming, or yoga can make a difference.

Stay connected with others rather than withdrawing. Maintaining social connections, even when you don’t feel like it, can help prevent the isolation that worsens depression.

Create a comfortable, well-lit environment at home and work. Opening curtains during the day, sitting near windows, and using bright indoor lighting can all help.

When to Seek Professional Help

It’s important to recognise when self-care strategies aren’t sufficient and professional support is needed. You should seek help if:

Your symptoms are affecting your ability to work, maintain relationships, or carry out daily activities. You’re experiencing thoughts of self-harm or suicide (in which case, seek urgent help immediately). Your symptoms persist despite trying self-help strategies. You’re concerned about your alcohol or substance use as a way of coping. You have a history of bipolar disorder and notice mood changes, as seasonal patterns can trigger manic or depressive episodes.

At Brighton Therapy Clinic, we’re here to support you through difficult times. Our transparent fee structure ensures you can find appropriate support within your budget, and we offer cost-sensitive therapy options to make mental health support accessible.

Prevention and Long-Term Management

For those who’ve experienced SAD in previous years, taking proactive steps before symptoms begin can be valuable. This might include starting light therapy in early autumn before symptoms typically appear, maintaining regular exercise and outdoor time throughout the year, or planning therapy sessions to begin before the darker months.

Understanding your personal triggers and early warning signs allows you to respond quickly when symptoms start to emerge. Keeping track of your mood, energy levels, and sleep patterns can help you identify patterns and take action early.

It’s also helpful to prepare practically for winter by planning activities you enjoy, scheduling regular social contact, and ensuring your home environment is conducive to wellbeing during darker months.

Frequently Asked Questions

How long does seasonal affective disorder last?

Winter-onset SAD typically begins in late autumn or early winter (October to November) and improves in spring or early summer (March to May). Individual experiences vary, but symptoms usually follow this predictable pattern each year. The duration of symptoms generally corresponds to the period of reduced daylight in your area.

Can you have seasonal affective disorder in the summer?

Yes, though it’s much less common. Summer-onset SAD affects a smaller percentage of people and presents with different symptoms, including insomnia, decreased appetite, weight loss, agitation, and increased anxiety rather than the hypersomnia and increased appetite typical of winter SAD. The exact mechanisms aren’t fully understood but may relate to increased heat, humidity, or longer daylight hours.

Is seasonal affective disorder the same as clinical depression?

SAD is a subtype of major depressive disorder characterised by its seasonal pattern. During episodes, people with SAD experience the same symptoms as clinical depression. The key difference is the predictable seasonal onset and remission. However, the impact on mental health and functioning is just as significant as non-seasonal depression, and it requires proper treatment.

Can light therapy really help with seasonal depression?

Yes, light therapy has substantial evidence supporting its effectiveness for winter-onset SAD. When used correctly (typically 10,000 lux for 20-30 minutes each morning), light therapy can significantly improve symptoms for many people. It works by helping to reset your circadian rhythm and may increase serotonin levels. However, individual responses vary, and some people may need additional treatments alongside light therapy.

Should I see a therapist or my GP first for seasonal depression?

Either is appropriate. Your GP can assess your symptoms, rule out other medical causes, and discuss treatment options including medication if needed. A therapist can provide psychological support and evidence-based therapy for SAD. At Brighton Therapy Clinic, we offer a free initial consultation to assess your needs and can work collaboratively with your GP if appropriate. The most important thing is seeking support rather than struggling alone.

Will seasonal affective disorder go away on its own?

While SAD symptoms typically improve naturally as daylight increases in spring, the condition usually recurs the following winter without treatment. Leaving SAD untreated can lead to complications including social withdrawal, work or school difficulties, substance misuse, and worsening mental health. Effective treatment not only helps with current symptoms but can also reduce the severity of future episodes, making professional support worthwhile.

Get Support for Seasonal Affective Disorder in Brighton and Hove

Seasonal affective disorder significantly impacts mental health, but effective treatments are available. Whether you’re experiencing seasonal depression for the first time or have struggled with it for years, professional support can make a meaningful difference to your wellbeing.

At Brighton Therapy Clinic, we understand the challenges of living with seasonal mood changes. Our experienced team offers personalised therapy in a supportive, non-judgemental environment. We take the time to understand your individual circumstances and match you with a therapist who’s right for your needs, preferences, and budget.

Located at 175 Westbourne Street in Hove, we’re easily accessible for people across Brighton and Hove seeking support for seasonal affective disorder and other mental health concerns.

Don’t let seasonal depression diminish your quality of life. If you’re struggling with low mood, fatigue, or other symptoms of SAD, we encourage you to reach out. Our free initial consultation with a senior practitioner is a supportive first step towards feeling better.

To find out more about how we can help or to book your free consultation, please get in touch via our contact page. We’re here to support you through the darker months and beyond.