About Seasonal Affective Disorder (SAD)

Overview

Seasonal affective disorder (SAD) is a type of depression that occurs in a recurring seasonal pattern. It is also known as major depressive disorder (MDD) with seasonal patterns. SAD typically starts in the fall or winter and improves in the spring or summer. People with SAD tend to follow a consistent pattern each year, feeling depressed during the affected seasons but feeling well during the rest of the year. The condition affects between 0.5% and 2.4% of people in the United States, with a higher prevalence among women and young adults, especially those living farther north.

The symptoms of SAD include depressed mood, anxiety, irritability, lack of energy or fatigue, restlessness or slowed down movements, reduced physical activity, increased appetite (especially for carbohydrates) sleep disturbances, loss of interest in activities, feelings of guilt or worthlessness, difficulty concentrating or making decisions, low libido, and thoughts of death or suicide. SAD is thought to be caused by reduced exposure to sunlight, which can disrupt the body’s circadian rhythms (body’s natural clock) and affect mood. Treatment options for SAD include medication, psychotherapy, light therapy, and dietary supplements like vitamin D.

Causes and Risk Factors

The exact disease mechanism and causes of seasonal affective disorder (SAD) are not fully understood, but there are several factors that may contribute to its development.

Disease causes of SAD:

Decreased sunlight exposure in winter and increased exposure in spring and summer can disrupt the natural biological clock (circadian rhythm) that regulates hormones, sleep, and moods.
Abnormal levels of serotonin and melatonin, hormones involved in regulating mood and sleep, may disrupt the circadian rhythm.
Research suggests that individuals with high levels of serotonin transporters may be more likely to develop SAD.

Non-modifiable risk factors cannot be changed or controlled. This includes:

Genetic predisposition: Variations in multiple genes that regulate circadian rhythm (the body’s internal clock) have been identified in individuals with SAD.
Family History: Having a family history of depression or SAD increases the risk of developing the disorder.

Modifiable risk factors can be influenced or changed. These include:

Sunlight exposure: Increasing exposure to natural light during the day, especially in the morning, may help alleviate symptoms of SAD.
Exercise: Regular physical activity has been shown to improve mood and reduce symptoms of depression.
Social support: Maintaining social connections and seeking support from friends and family can help manage SAD symptoms.
Stress management: Developing effective coping strategies for stress can help reduce the impact of SAD.
Geography: SAD is more common in regions farther from the equator, where there is less sunlight during the winter months.

It's important to note that these risk factors may vary from person to person. If you suspect you have SAD or are at risk, it's best to consult with a healthcare professional for an accurate diagnosis and personalized advice.

Symptoms

Early symptoms of seasonal affective disorder (SAD) may include:

Sadness
Gloomy outlook
Feeling hopeless, worthless, and irritable
Loss of interest or pleasure in activities you used to enjoy
Changes in energy levels, such as low energy and fatigue during the winter pattern or increased restlessness and agitation during the summer pattern.
Difficulty sleeping or oversleeping
Carbohydrate cravings and weight gain

As SAD progresses or becomes more severe, additional symptoms may occur, such as:

Daytime fatigue
Difficulty concentrating
Increased irritability
Lack of interest in social activities
Reduced sexual interest

In severe cases, thoughts of suicide may also be experienced. It's important to note that SAD can affect people differently, and the symptoms may vary based on the type of SAD (winter-pattern or summer-pattern). If you suspect you may have SAD or are experiencing any of these symptoms, it's essential to speak with a healthcare professional for an accurate diagnosis and appropriate treatment options.

If you or someone you know are struggling or in crisis with anxiety, depression or suicidal thoughts, help is available. Call or text 988 or chat 988lifeline.org/chat to connect with trained crisis counselors.

Diagnosis

To diagnose seasonal affective disorder (SAD), healthcare professionals typically rely on a thorough evaluation of symptoms and medical history. They may also use the following examinations, tests, and procedures:

Seasonal Pattern Assessment Questionnaire (SPAQ): The SPAQ is a commonly used screening tool for SAD. It assesses an individual's seasonality by measuring fluctuations in sleep, social activity, mood, weight, appetite, and energy.
Diagnostic Criteria: The healthcare provider will assess your symptoms according to the criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). This helps determine if your symptoms align with major depressive disorder (MDD) with a seasonal pattern.

To determine the stage or severity of SAD, additional examinations, tests, and procedures may include:

Clinical interview: A healthcare professional may conduct a detailed interview to gather information about the duration, intensity, and impact of symptoms.
Mental health assessment: This evaluation may involve psychological questionnaires or assessments to assess mood, cognition (thinking), and overall mental well-being.
Physical examination: A physical examination can help rule out other medical conditions that may be causing or contributing to the symptoms.
Blood tests: Blood tests may be done to rule out any underlying medical conditions that could be causing or worsening depressive symptoms.

It's important to note that these evaluations are typically performed by healthcare professionals who specialize in mental health. They will use their clinical judgment to make an accurate diagnosis and determine the appropriate treatment plan for each individual.

Treatment Options

The goals of treatment for seasonal affective disorder (SAD) are to relieve symptoms, improve mood, and enhance overall well-being. Here are the different treatment options and how they work:

Medication:

Antidepressants, such as selective serotonin reuptake inhibitors (SSRIs), are commonly used to treat SAD. They increase the levels of serotonin in the brain, which helps regulate mood.
Specific medications like fluoxetine, sertraline, citalopram, escitalopram, and paroxetine are often prescribed for SAD. Bupropion is also approved for treating SAD and works by affecting the levels of dopamine and norepinephrine in the brain.

Therapies:

Cognitive Behavioral Therapy (CBT) is a type of talk therapy that helps individuals identify negative thought patterns and develop coping strategies to replace them with positive thoughts and behaviors. CBT can be effective in managing SAD symptoms.

Therapeutic procedures:

Light therapy involves using a specialized light box that emits bright light to mimic natural sunlight. It helps regulate circadian rhythms and improve mood.
Dawn simulator is another treatment option that uses a time-activated light to simulate sunrise, stimulating the body's internal clock.

Health behavior changes:

Regular exercise and exposure to natural sunlight can help alleviate SAD symptoms.
Adopting a balanced diet with lean protein, fruits, and vegetables can also contribute to overall well-being.

Other treatments:

Vitamin D supplements may be used, although their effectiveness is still being studied.

Remember, it's important to consult with your healthcare professional about the best treatment options for your individual situation.

Medication dosing may be affected by many factors. Check with your health care professional about dosing for your individual situation. Other side effects can occur. Check with your health care professional or read the information provided with your medication for additional side effect information.