Seasonal Depression: What Is Seasonal Affective Disorder and How Can It Be Treated?

Seasonal depression is related to changes in seasons. Seasonal Affective Disorder typically begins and ends around the same time of the year and can severely impact an individual's health. However, SAD is a manageable condition. Learn all about seasonal depression and how to activate your body’s natural defenses against it.

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You might wonder why some people feel down when the days get shorter, and the temperatures drop. Well, it's about more than just missing those sunny beach days or simply feeling a little blue because the weather is gray. For some people, the changing seasons can trigger a form of depression called seasonal depression.

Typically, seasonal depression is much more than just "winter blues." It's a serious mood disorder that comes and goes with the seasons, beginning in the late fall or early winter and going away during the late spring and early summer.

People with seasonal affective disorder (SAD) usually experience symptoms similar to major depressive disorder sapping their energy, causing them to feel sad and withdrawn, making it difficult to enjoy activities they used to love. Moreover, it can lead to changes in eating habits and sleeping patterns.

In this article, we're going to tell you more about this type of depression that is related to the changing of seasons and how to identify it. We'll also provide some practical tips and advice on how to manage it.

So, whether you're directly affected by depression as the seasons change or want to learn more about it, keep reading.

What is Seasonal Depression?

Seasonal depression, formally known as Seasonal Affective Disorder (SAD), is a mood disorder characterized by recurrent depressive episodes that start and end around the same time each year. The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) classifies this type of depression as Major Depressive Disorder with Seasonal Patterns.

If you're like most people who get depressed with the changing seasons, your symptoms start in Autumn and last throughout winter, draining your energy and making you feel moody and low.

However, some people may experience a rare form of depression during the spring and summer months, known as “summer depression or summer-onset SAD." Others may experience a milder form of SAD known as the “winter depression.”

According to the American Academy of Family Physicians, SAD affects about 4 to 6% of adults in the United States annually. And up to 20% may have winter blues.

SAD is more prevalent in certain regions—countries farther from the equator typically have higher rates of seasonal affective disorder. Women are also more likely to be affected than men. In addition, people between 18 and 30 years old are more likely to be diagnosed with SAD than any other age group.

Risk Factors for Seasonal Depressive Disorder

Several risk factors can increase your chances of developing seasonal depression, including:

A family history of SAD or other forms of depression
Living far from the equator
Having another type of mental health disorder (e.g., bipolar disorder, schizophrenia)
Low level of vitamin D
Having had previous episodes of SAD
Experiencing high-stress levels

Signs and Symptoms of Seasonal Affective Disorder (SAD)

Seasonal depressive symptoms are similar to clinical depression but with a seasonal pattern. Common signs and symptoms of SAD include:

Changes in appetite, especially carbohydrate cravings for starchy and sweet foods
Difficulty concentrating or lack of focus
Feeling sad, sluggish, or tired
A decrease in energy levels
Social withdrawal and isolation
Feelings of depression, hopelessness, worthlessness, or guilt
Irritability and mood changes
Persistent sadness
Sleeping too much or too little
Loss of interest in activities once enjoyed
Change in appetite or weight gain

Winter Depression or Fall and Winter SAD

People with winter-onset seasonal affective disorder may experience symptoms such as:

Sleep problems
Changes in appetite
Weight gain
Tiredness or low energy

Summer Depression or Spring and Summer SAD

People with summer-onset seasonal affective disorder may experience symptoms such as:

Agitation or anxiety
Irritability
Insomnia
Difficulty concentrating
Loss of appetite

The Science Behind Seasonal Affective Disorder (SAD)

So far, you know what SAD is, its common signs and symptoms, and its risk factors. However, one question remains — why does SAD happen? Understanding this is the first step toward helping treat SAD.

The exact cause of seasonal depression is still unknown, but several scientific theories have tried to explain its onset. These include:

1. Biological Clock or Circadian Rhythm Hypothesis

One prominent theory suggests that reduced exposure to sunlight during the winter months plays a significant role in developing depression as the seasons change. Our bodies have an internal clock, or circadian rhythm, regulating various physiological processes like sleep, wake, and mood.

Therefore, the body's internal clock is thrown off balance during shorter days with less sun because you don't get enough natural light. This disrupts the balance of your body's internal 24-hour cycle of biological processes, leading to feelings of depression.

2. Melatonin Hypothesis

Another theory relates to melatonin, the body's natural sleep hormone, which regulates sleep and wake cycles. Typically, our body produces melatonin in higher amounts when it is dark and lower amounts when it is light.

Thus, in the winter months, when daylight hours are shorter, melatonin production may be prolonged, leading to disruptions in sleep patterns and potentially contributing to depressive symptoms.

3. An Imbalance of Serotonin

Serotonin, often called the "feel-good" hormone, is a neurotransmitter responsible for regulating mood. Production of serotonin is regulated by light exposure, and reduced sunlight may lead to an imbalance in serotonin production, causing a chemical imbalance in the brain that triggers depressive symptoms.

4. Vitamin D Deficiency

Deficits in vitamin D are another factor that can contribute to SAD. Your body produces Vitamin D when sunlight hits the skin, and it helps with energy levels, mood regulation, and other bodily processes. With less daylight in the winter, people with SAD may have low levels of vitamin D, leading to feelings of depression, anxiety, fatigue, and apathy — all classic symptoms of seasonal affective disorder.

5. Role of Genetics

It is also believed that genetic factors can also play a role in SAD. People who have family members with clinical depression or other mood disorders are more likely to develop this disorder as well.

How Is Seasonal Depression Diagnosed?

If you think you may be suffering from seasonal affective disorder, talking to a mental health professional, or taking a depression self-test is essential.

A diagnosis of seasonal depression usually involves assessing your symptoms and medical history and undergoing physical examinations or psychological testing. This is because the main characteristic of SAD is mood and behavior shifts along with the calendar. It is also a condition that can mimic other mood disorders, such as major depression or chronic fatigue syndrome.

The health specialist may use the Seasonal Pattern Assessment Questionnaire (SPAQ) to help diagnose your condition. This questionnaire examines if your symptoms meet the criteria of SAD.

Here are some of the criteria used to diagnose seasonal affective disorder:

You have experienced symptoms of major depression or any of the specific symptoms mentioned above.
Your depressive episodes only occur during specific seasons (usually in the winter or summer months) for at least two consecutive years. However, not all individuals with SAD experience symptoms each year.
Your depressive symptoms are much more frequent than any other episodes you may have had at other times of the year.
The periods of depression are followed by periods without depression.

It is important to note that SAD is different from a depressed mood around the holidays or in reaction to stress because of the holiday season. Both of these would be considered situational or reactive depression, and a person’s personality and life history can greatly impact how they handle potentially stressful holiday gatherings.

In contrast, seasonal affective disorder is a biological and/or psychological reaction directly related to the change of seasons — not the events of the season.

Treatment for Seasonal Affective Disorder (SAD)

There are a variety of ways to treat SAD. Treatments are classified into four main categories that may be used alone or combined.

1. Light Therapy

Since the 1980s, light therapy, also known as phototherapy, has been the mainstay of Fall-onset seasonal affective disorder treatment. It aims to compensate for the reduced exposure to natural sunlight during the darker months.

Light therapy involves sitting in front of a bright light box (10,000 lux) daily, usually first thing in the morning, from late fall to spring. It typically lasts 30-45 minutes.

While the lightbox is 20 times brighter than ordinary indoor light, it can filter out potentially harmful UV rays, making them safe. However, this doesn't mean that everyone can use them. For instance, people with certain eye diseases or medications that increase sun sensitivity may require alternative treatments or supervised light therapy.

2. Psychotherapy

Also known as talk therapy, psychotherapy is another SAD treatment option. It focuses on psychological aspects (how your brain functions) and social aspects (how you interact with others). Cognitive behavioral therapy (CBT), in particular, is an effective type of psychotherapy that can help you:

CBT has also been adapted for SAD and is called CBT-SAD. It involves individual or group sessions over six weeks, typically two per week. The focus is on replacing negative thoughts about winter with more positive ones and using a process known as behavioral activation to identify and schedule pleasant activities to combat reduced interest in the winter months.

Besides CBT, counseling and psychodynamic psychotherapy are other types of talk therapy used to treat seasonal affective disorder. During psychodynamic psychotherapy, you talk to a trained counselor about how you feel about yourself and others and discuss experiences in your past that may be affecting how you feel today. The aim is to find any patterns in your behavior and thought processes that may be contributing to your depression.

3. Medication

Medication for seasonal affective disorder may be used if the other treatments are not working or your SAD symptoms are severe. Antidepressants, such as selective serotonin reuptake inhibitors (SSRIs), help regulate neurotransmitters in the brain, like serotonin, which can impact your mood. Commonly prescribed antidepressants for SAD include fluoxetine, citalopram, sertraline, paroxetine, escitalopram, and bupropion.

The US Food and Drug Administration (FDA) also approves bupropion as another antidepressant in extended-release form. It is used to prevent the recurrence of seasonal major depressive episodes when taken daily from the Fall until the following early spring.

As with most medications, there can be side effects that could include nausea and fatigue. Therefore, talking to your doctor about the potential risks and benefits is essential. You may need to try several antidepressant medications before finding the right one.

4. Vitamin D

Although not commonly used, your doctor may also recommend vitamin D supplements as a potential treatment for SAD. This is because low levels of vitamin D, either caused by insufficient dietary intake or lack of exposure to sunlight, have been linked to SAD. However, there is limited research on the efficacy of vitamin D supplementation in treating SAD and other dietary supplements for this condition.

It is important to note that even if you do not have symptoms of SAD if your Vitamin D levels are low, this is still an issue that needs to be treated.

Holistic Approaches to Help Manage SAD

Along with traditional treatments, holistic approaches can combat SAD symptoms. While these therapies are not considered a primary treatment for seasonal depression, they may help manage symptoms.

Here are a few self-care options for to consider if you have SAD:

1. Exercise

As with other forms of depression, regular exercise can help combat seasonal affective depression. First, it helps offset weight gain, a common symptom associated with SAD. Secondly, exercising outdoors in natural sunlight helps offset the reduced exposure to daylight during winter. And finally, exercise has been proven to be a great stress reliever and mood booster.

If outdoor exercise is not possible due to cold or snowy weather, try utilizing other forms of cardio, such as a treadmill, stationary bike, or elliptical machine set up near a window at home or the gym.

2. Prepare Your Mind in the Fall

Preparing for the fall-to-winter transition isn't just about stocking up on seasonal items — consider preparing your mind, too. This helps reduce the feeling of helplessness and confusion when the winter blues set in since you know how to cope best.

According to Kim Burgess, a renowned psychologist and an adjunct associate professor of psychiatry and behavioral sciences at the George Washington University School of Medicine and Health Sciences in Washington, DC, "It's better to set yourself up for the winter season by starting in the fall season—doing enjoyable activities, initiating friend group chats and outings, choosing fun hobbies, and engaging in clubs or community service."

3. Try Aromatherapy

Traditional medicines have used essential oils for centuries to improve emotional well-being. Aromatherapy is a form of alternative medicine that uses essential oils from plants and herbs to promote relaxation and alleviate stress. Consequently, research shows that certain essential oils, such as lavender and bergamot, can help reduce symptoms of depression like anxiety, restlessness, sleep disruption, and fatigue.

According to John Hopkins Medicine, the safest way to use aromatherapy is through body oils, aroma sticks, and jewelry made with absorbent materials to apply essential oils. The organization advises against ingesting essential oils or using essential oil diffusers.

4. Incorporate Daily Gratitude Practices

Practicing gratitude daily can be a powerful way to counteract the negative feelings associated with SAD. Taking a few moments each day to reflect on the small positives—whether it’s a warm cup of tea, a favorite song, or a moment of sunlight—can gradually shift your focus and boost your mood. Scientific studies show that even small acts of gratitude can help reduce stress and increase resilience, which can be especially beneficial during the darker months.

Consider keeping a gratitude journal or simply listing one or two things you’re thankful for each day. This practice doesn’t require a major time commitment but can make a big difference over time. By focusing on the good, even on challenging days, you can create pockets of positivity that lighten your outlook and help you feel more connected and grounded.

Help is Available for Seasonal Depression

No matter what type of treatment you choose for SAD, it is essential to remember that there are no “quick fixes” or “one size fits all” approaches. Working with a mental health professional is the best way to find a treatment plan that works for you. Additionally, having a support system of family, friends, and mental health professionals can be an invaluable resource in managing SAD symptoms.