What Is Seasonal Affective Disorder (SAD)? 22 Signs, Causes, And How To Deal

Seasonal affective disorder, or SAD, is a type of depressive disorder that is related to seasonal changes. It is also commonly known as seasonal depression and major depressive disorder (MDD) with a seasonal pattern.

What Is Seasonal Affective Disorder?

Seasonal affective disorder is a mood disorder that is experienced every year at the same time and is also called summer or winter depression. SAD is considered to be a subtype of depression¹

Studies ² have shown that SAD gradually decreases one’s energy and can eventually lead to full-blown major depressive disorder. According to research ³, seasonal depression can be commonly observed among people who live further away from the equator, and the symptoms usually resolve in a few months with increased daylight in the spring.

SAD affects various significant aspects of an individual’s life, such as:

As a result, it can cause several complications that include:

Lack of interest in social interaction
School and work-life problems
Difficulties in performing daily activities
Suicidal thoughts
Anxiety and eating disorder

As per research ¹⁰, seasonal depression affects around 10% of the global population. The prevalence is completely related to the latitude since it is dependent on the duration of daylight. According to a 2015 study ¹¹, women are four times more likely than men to experience this disorder.

SAD vs. Winter Blues

Seasonal affective disorder is more severe than winter blues ¹², which is a milder version of this condition. Winter blues refers to a feeling of depression associated with the cold and darkness of winter but it often goes away without treatment.

Another condition that is often confused with the seasonal affective disorder is “holiday depression”, which usually occurs during festivals and vacations.

Read More About Holiday Depression Here

Case Example

Leena had moved to Scotland for her Ph.D. about 3 years ago. Having been born and brought up in the plains of India, she had been used to a warm climate all her life and was still struggling to adjust to the consistently cold temperatures of Edinburgh.

The initial joy of watching the snowfall and skiing on ice had worn out very soon. In fact, with the celsius dropping close to 0 degrees in winter, Leena could barely function. She had never thought she would crave sunlight to such an extent.

For the past three years, Leena would invariably start feeling low, anxious and cranky around November and this would continue until February.

Her colleagues noticed her productivity levels significantly drop around these months. She would also take frequent leaves from work, saying that she was not feeling well. Whenever her friends called her to hang out, she would make up an excuse to stay indoors.

It was safe to say that Leena dreaded winters in Scotland. But this time she decided to talk to someone about it, because she could not afford to slack off at work anymore, and she really wanted to make the best of the season.

After consulting a therapist, she came to learn a great deal about her condition, which was called seasonal affective disorder, and realized that it was possible for her to feel better.

Symptoms Of SAD

Seasonal affective disorder symptoms may range from mild to severe depending on the changes in season, and individual differences. People usually start to experience the symptoms of SAD from October/November till February/March ¹³). Although less common, SAD can also occur in summer.

Signs and Symptoms Of Seasonal Affective Disorder

Generally, there are two types of symptoms of seasonal affective disorder depending on the season:

A. Winter symptoms

Most people experience severe symptoms during fall/winter, such as:

Consistent low mood
Appetite changes and weight gain ¹⁴
Changes in sleeping pattern ¹⁵
Tiredness or lethargy ¹⁶
Overeating due to carbohydrate craving ¹⁷
Difficulty in thinking and concentrating
Feeling sad, cranky, and irritated
Self-harm thoughts ¹⁸
Social withdrawal ¹⁹
Reduced sexual interest ²⁰
Feeling worthless and guilty ²¹
Aches and pains without a medical reason ²²
Desire for extreme physical activity ²³
Feeling angry, anxious, and stressed ²⁴
Crying without any reasonable trigger
Interpersonal difficulties ²⁵

B. Summer symptoms

The mild summer symptoms include:

A 2008 study ³¹ claims that the symptoms of seasonal affective disorder can last for 4 to 5 months in a year. One can experience these symptoms at any age, but they typically start between the age of 18 to 30 ³². Over time, the symptoms may become severe and affect one’s day-to-day activities.

If you face any of the above seasonal symptoms for two consecutive years, it is recommended that you consult a mental health professional.

Causes Of SAD

The exact causes of seasonal affective disorder are still unknown, there are some significant factors that can trigger the symptoms, such as:

1. Reduced Sunlight

Seasonal affective disorder is often believed to be associated with reduced exposure to sunlight ³³ in the winter months. An important theory ³⁴ claims that reduced daylight may disrupt the functioning of a significant part of the brain called the hypothalamus.

2. Circadian rhythm

Sunlight is extremely essential for several important functions in our body. According to a 2006 study ³⁵, as a result of decreased sunlight the biological clock or the circadian rhythm ³⁶ of the human body often gets disturbed, thus affecting our sleep-wake-cycle, hormones, appetite, and mood. This condition eventually leads to feelings of depression and makes one feel groggy, cranky, anxious, sleepy, and disorientated.

3. Latitude

Research ³⁷ suggests that people who live in places that have long winter nights and less sunlight because of the higher altitude are more likely to experience the symptoms of seasonal affective disorder. SAD is more common among the citizens of Canada and Alaska since the sun in these places disappears for months at a time.

The reduced sunlight exposure and the frigid conditions increase the risk of seasonal mood disorder in people of such countries. Contrarily, the sunnier and temperate weather of Florida reduces the risk of being diagnosed with seasonal depression.

4. Overproduction of melatonin

Studies ³⁸ have found that the human brain releases melatonin during the night and helps us to fall asleep. Decreased sunlight exposure causes overproduction of melatonin ³⁹ hormone in our body. As melatonin regulates our sleep patterns and mood, increased melatonin levels may make us feel sleepy and lethargic at inconvenient times.

5. Lesser dopamine production

Dopamine plays a critical role in light or dark adaptation and has a mutually inhibitory relationship with melatonin ⁴⁰. Increased melatonin often causes lesser dopamine production ⁴¹ in the body. As dopamine develops a sense of pleasure and happiness ⁴² in people, decreased dopamine level makes people depressed and emotionally unwell.

6. Decreased serotonin levels

Serotonin ⁴³ is a neurotransmitter that affects people’s moods. Reduced sunlight exposure causes a drop in serotonin production. A 2013 study ⁴⁴ says that serotonin deficiency may lead to depression along with other symptoms, including appetite changes, memory problems, drowsiness, and low interest in sexual desire.

7. Vitamin D deficiency

Sunlight is a great source of vitamin D in the human body. A 2015 research paper ⁴⁵ mentions that vitamin D and serotonin levels are interlinked with each other. During winter, our body experiences vitamin D deficiency followed by decreased serotonin levels and several depression symptoms.

Risk factors for Seasonal Affective Disorder

Apart from causes such as low sunlight etc., certain other factors may also increase the risk of developing SAD, such as:

Family History ⁴⁶: Having a family member with a psychological disorder may increase the risk of being diagnosed with seasonal depression.
Gender ⁴⁷: Seasonal depression is more common among women than men.
Age ⁴⁸: Younger adults tend to be diagnosed with this mood disorder more than older adults.
Prior medical history ⁴⁹ of bipolar disorder or major depressive disorder.

Read More About Major Depressive Disorder (MDD) Here

Diagnosis Of SAD

Sometimes, it is extremely difficult to detect seasonal affective disorder even with proper evaluation, as other types of mental disorders may cause similar symptoms.

To be clinically diagnosed with seasonal affective disorder, you would have experienced depressive symptoms during a particular season (summer or winter) for at least more than two consecutive years ⁵⁰.

A mental health professional, such as a psychologist or a psychiatrist usually takes a detailed history and conducts a mental status examination along with certain psychometric assessments to diagnose SAD. The most common test for screening seasonal depression is the Seasonal Pattern Assessment Questionnaire (SPAQ) ⁵¹.

Treatment For SAD

Seasonal affective disorder treatment varies depending on your medical history and the severity of your symptoms. It is important to consult a doctor about which treatment is best suited for you. The following are some of the most common beneficial treatments ⁵² for seasonal affective disorder:

1. Bright light therapy

Experts recommend the use of bright light therapy ⁵³ for seasonal affective disorder, as research ⁵⁴ suggests that this kind of therapy may be a suitable replacement for the role of natural outdoor light and can even work as an antidepressant. Light therapy can be done either with a lightbox or a dawn simulator.

A Lightbox ⁵⁵ delivers light that is ten times more intense than normal domestic light. One needs to sit 2 feet away from the lightbox for at least the first hour after waking up in the morning.

A 2009 study ⁵⁶ claims that the full-spectrum light of the lightbox indirectly shines into the eyes and has the ability to significantly reduce SAD symptoms. However, you should not stare directly at the light for a longer time and doing so may cause hypomania ⁵⁷ in people who also have bipolar disorder.

Read More About Bipolar Disorder Here

b. Dawn simulator

A dawn simulator refers to a device that increases the amount of light in the bedroom. This device can imitate the rising sun in the morning and help you wake up. It gradually increases the light, mimicking sunlight. Studies ⁵⁸ have found that dawn simulators can help reset one’s circadian rhythm and improve mood.

However, a 2013 study ⁵⁹ has found that light therapy can also cause several side effects, such as agitation or irritability, headaches, eye strain, sleep disorders, blurred vision, and tiredness.

Read More About Sleep Disorders Here

2. Psychotherapy

Psychotherapy ⁶⁰ is another effective treatment option for seasonal affective disorder and it is supposed to have long-lasting benefits. One of the most common psychotherapies used to treat seasonal depression is cognitive-behavioral therapy (CBT) ⁶¹.

Read More About Cognitive Behavioral Therapy (CBT) Here

3. Medication

If the symptoms of seasonal affective disorder are severe and cannot be treated with light therapy or psychotherapy, prescription medicines can be used for treatment.

Antidepressants ⁶² such as bupropion have been found to significantly reduce SAD symptoms. Bupropion is believed to be most effective if taken at the start of the winter before the symptoms appear. However, it is extremely important to know the adverse side effects of antidepressant medication before starting to take them.

Remember to always consult a doctor in case of any problems and never stop medication on your own.

Read More About Antidepressants And Their Side Effects Here

4. Mind-body connection

There are some extremely beneficial mind-body techniques that people often use to deal with seasonal affective disorder. The techniques include:

Read More About Meditation Here

5. Vitamin D treatment

Research ⁶⁸ claims that SAD is associated with vitamin D deficiency. Doctors often recommend seasonal depression patients to increase their vitamin D intake through their diet, exposure to sunlight, or vitamin supplements. That said, studies examining the effectiveness of vitamin D treatment have inconclusive findings.

How To Deal With Seasonal Affective Disorder

Besides professional treatment, there are certain other effective ways ⁶⁹ to cope with seasonal affective disorder, such as:

Get as much natural sunlight as possible.
Follow a healthy lifestyle. Eg: get enough sleep, do regular physical exercise, eat balanced meals, and drink plenty of water.
Try to spend more time with your loved ones.
Learn to practice meditation or other mindfulness techniques to manage your stress better.
If possible, plan a winter or summer vacation based on your seasonal depression pattern.
Do things that make you happy. Eg: Go to a movie, do gardening, listen to soothing music, take part in religious and social activities, etc.
Try not to take any important decisions until the depression has lifted.
Try to stay focused and have faith in the treatment process.

How To Help Someone With Seasonal Depression

If your friend, family member, or partner seems to be suffering from seasonal depression and you’d like to extend a helping hand, here are some things you could do for them:

Try to be a good listener.
Encourage them to take professional help and adhere to the treatment plan.
Take a walk with them, or accompany them in other activities that they might feel too tired to do.
Contact a support group that will help them deal with their symptoms better.
Let them know that you love and support them even in the tough times.
Try to do something special for them that might cheer them up.

Takeaway

Seasonal affective disorder is a type of seasonal depression that people usually experience from the winter till late spring or early summer. People with SAD often experience common depression symptoms according to seasonal changes.

Though it takes a lot of time, most people recover fully with proper treatment and medication. Healthy lifestyle choices can also make it easier for people to deal with the severity of the symptoms.

At A Glance

Seasonal affective disorder (SAD) is a type of mood disorder associated with seasonal changes.
People with SAD experience certain mild to severe symptoms, such as daytime fatigue, sadness, social withdrawal, among others.
Latitude differences, melatonin overproduction, reduced serotonin level, vitamin D deficiency are some of the significant contributing factors of seasonal depression.
Seasonal affective disorder can be diagnosed with the help of various physical examinations, laboratory tests, and psychological evaluations.
Doctors often prescribe bright light therapy, cognitive-behavioral therapy, and antidepressant medication for SAD.

Frequently Asked Questions (FAQs)

1. Can seasonal depression turn into depression?

Since sunlight is directly associated with serotonin production, people who have SAD due to low levels of serotonin may be at risk of developing severe depression.

2. What do schizophrenia and seasonal affective disorder have in common?

Schizophrenia is a psychotic disorder, whereas SAD is a mood disorder with a seasonal pattern. However, research suggests that people in high latitudes with schizophrenia are prone to developing seasonal affective disorder as well. ⁷⁰

3. How to Beat Seasonal Affective Disorder Naturally?

Transcendental meditation, yoga, and other forms of meditation along with a diet rich in vegetables, proteins, complex carbohydrates, and unprocessed foods have been found to be useful for seasonal affective disorder. ⁷¹

4. Does vitamin D help with seasonal depression?

Yes. Since a lack of vitamin D can lead to seasonal depression, doctors often recommend it for treatment.

5. When does seasonal depression hit the hardest?

The winter months of December, January and February are considered to be the worst for seasonal depression.

6. How do you prevent seasonal depression?

Due to the predictable nature of seasonal affective disorder, it is relatively easier to prevent it by beginning treatment at the start of the season or planning a vacation to a warmer place during that time.

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Seasonal Affective Disorder (SAD)

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