About Seasonal Affective Disorder (SAD)

What Is Seasonal Affective Disorder?

Seasonal affective disorder (SAD) is a type of depression that occurs in a recurring seasonal pattern. Clinically, it may be described as major depressive disorder (MDD) with a seasonal pattern. SAD most often starts in the fall or winter and improves in the spring or summer, although a less common pattern can begin in spring or summer and improve in fall or winter. People with SAD tend to experience a similar seasonal pattern each year, with symptoms during the affected season and improvement during the rest of the year. SAD is more common among women, younger adults, and people living farther from the equator, where winter daylight hours are shorter.

Symptoms of seasonal affective disorder (SAD) can include depressed mood, anxiety, irritability, lack of energy or fatigue, restlessness or slowed movements, changes in physical activity, increased appetite or carbohydrate cravings, sleep disturbances, loss of interest in activities, feelings of guilt or worthlessness, difficulty concentrating or making decisions, reduced sexual interest, and thoughts of death or suicide. SAD is thought to be related to changes in daylight exposure that may disrupt circadian rhythms and affect mood-regulating brain chemicals, including serotonin and melatonin. Treatment options may include light therapy, psychotherapy, antidepressant medication, and lifestyle strategies. Vitamin D may be considered when deficiency is present, but it is not a proven stand-alone treatment for SAD.

Causes and Risk Factors of Seasonal Affective Disorder

The exact causes of seasonal affective disorder (SAD) are not fully understood, but changes in daylight exposure, circadian rhythm, and mood-regulating brain chemicals may contribute to its development.

Possible biological contributors to seasonal affective disorder (SAD) include:

Reduced daylight exposure during fall and winter may disrupt the body’s internal clock, or circadian rhythm, which helps regulate sleep, hormones, and mood.
Changes in serotonin, a brain chemical involved in mood, and melatonin, a hormone involved in sleep timing, may play a role in SAD symptoms.
Vitamin D deficiency has been studied as a possible contributor, but the relationship between vitamin D and SAD is not fully established.

Non-modifiable risk factors cannot be changed or controlled. These include:

Genetic and family factors: SAD can run in families, and risk may be higher in people with a personal or family history of depression, bipolar disorder, or 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: Living farther from the equator is associated with higher risk because winter daylight hours are shorter.

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.

Seasonal Affective Disorder 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, such as low energy and fatigue in winter-pattern SAD or agitation and restlessness in summer-pattern SAD
Difficulty sleeping or oversleeping
Carbohydrate cravings, overeating, and weight gain, especially in winter-pattern SAD

As seasonal affective disorder (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 death or suicide may occur. SAD can affect people differently, and symptoms may vary based on whether the pattern occurs in fall/winter or spring/summer. If you think you may have SAD or are experiencing symptoms of depression, 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 visit 988lifeline.org/chat to connect with trained crisis counselors.

How Seasonal Affective Disorder Is Diagnosed

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:

Screening tools: A healthcare professional may use questionnaires, such as the Seasonal Pattern Assessment Questionnaire (SPAQ), to better understand seasonal changes in mood, sleep, appetite, weight, energy, and social activity. Screening tools do not diagnose SAD on their own.
Diagnostic criteria: A healthcare provider or mental health professional may assess symptoms using criteria from the Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR). SAD is not diagnosed as a separate disorder; it is typically described as major depressive disorder or bipolar disorder 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.

Seasonal Affective Disorder Treatment Options

The goals of treatment for seasonal affective disorder (SAD) are to reduce depressive symptoms, improve daily functioning, and help prevent symptoms from returning during future seasons. Treatment may include light therapy, psychotherapy, medication, lifestyle strategies, or a combination of these options.

Medication:

Antidepressants may be used to treat SAD, especially when symptoms are moderate to severe or do not improve enough with light therapy or psychotherapy. Selective serotonin reuptake inhibitors (SSRIs) are commonly used for depression and may be prescribed based on individual needs.
Bupropion extended-release is approved to help prevent seasonal major depressive episodes in people with a history of SAD. A healthcare professional can determine whether medication is appropriate and discuss possible benefits, risks, and side effects.

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, also called phototherapy, involves sitting near a specialized bright-light box, usually soon after waking. It can help regulate circadian rhythms and mood-related brain chemicals. People should ask a healthcare professional how to use light therapy safely, especially if they have bipolar disorder, eye disease, or take medicines that increase light sensitivity.
A dawn simulator may be considered for some people. It gradually increases light in the room before waking to simulate sunrise, but it should be used as part of a treatment plan discussed with a healthcare professional.

Health behavior and lifestyle 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 recommended if testing shows low vitamin D levels, but evidence is limited for using vitamin D alone to treat SAD.

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 and read the information provided with your medication for additional side effect information.