Seasonal Affective Disorder (SAD)

What Is Seasonal Affective Disorder?

Seasonal Affective Disorder (SAD) is a form of depression that typically occurs during certain times of the year, most commonly in the fall and winter months when daylight hours are shorter. People with SAD may notice their mood, energy and motivation drop as the days grow darker and colder.

While it’s often referred to as “seasonal depression,” SAD is more than just the winter blues. It’s a recognized mental health condition that can significantly affect daily life. Fortunately, with proper diagnosis and treatment, most people find relief and return to feeling like themselves again.

What Causes Seasonal Affective Disorder?

The exact cause of SAD isn’t fully understood, but researchers believe it’s linked to changes in light exposure that affect the body’s internal clock and mood-regulating chemicals.

Possible Contributing Factors Include:

• Reduced sunlight: Less daylight can disrupt your body’s circadian rhythm, which helps regulate sleep, mood, and hormones.
• Changes in serotonin levels: Lower sunlight exposure may reduce serotonin, a neurotransmitter that influences mood and happiness.
• Disruption in melatonin production: Shorter days and longer nights can affect melatonin levels, leading to changes in sleep and energy.
• Genetics: A family history of depression or SAD increases the risk.
• Geography: People living farther from the equator are more likely to experience SAD due to shorter daylight hours in winter.

Signs and Symptoms of SAD

SAD symptoms can vary in severity but often resemble those of major depression. They usually appear in late fall or early winter and fade during spring or summer.

Common Symptoms Include:

• Persistent sadness or depressed mood
• Low energy or fatigue
• Difficulty concentrating
• Sleep problems, such as oversleeping or trouble falling asleep
• Changes in appetite, especially craving carbohydrates or weight gain
• Loss of interest in activities once enjoyed
• Feelings of hopelessness or irritability

Some people experience a reverse pattern, developing SAD symptoms in spring or summer, though this is less common.

How Is Seasonal Affective Disorder Diagnosed?

A health care provider or mental health professional can diagnose SAD by reviewing your symptoms, medical history and how they relate to seasonal changes.

You may be asked about:

• The timing and pattern of your symptoms over the past few years
• Your sleep, energy, and eating habits
• Any family history of depression or mental health conditions

In some cases, lab tests may be ordered to rule out other conditions such as thyroid disorders or vitamin D deficiency, which can cause similar symptoms.

How to Treat Seasonal Affective Disorder

Effective treatment can help most people manage symptoms and improve their quality of life. Your provider may recommend one or more of the following options:

Light Therapy (Phototherapy):

One of the most common treatments, light therapy involves sitting near a specially designed light box that mimics natural sunlight. Regular exposure can help regulate mood-related brain chemicals and restore energy levels.

Psychotherapy:

Cognitive Behavioral Therapy (CBT) helps patients identify negative thought patterns and develop coping skills to manage seasonal mood changes.

Medication:

Antidepressants, especially selective serotonin reuptake inhibitors (SSRIs), may be prescribed to balance mood-regulating chemicals in the brain.

Lifestyle Adjustments:

• Spend time outdoors daily, even on cloudy days.
• Stay physically active to boost endorphins and energy.
• Eat a balanced diet rich in whole foods and nutrients.
• Maintain regular sleep routines.

How to Reduce the Risk of SAD

You can take steps to minimize or prevent seasonal mood changes, especially if you’ve experienced SAD before.

Helpful Prevention Tips:

• Start light therapy or increase outdoor activity early in the fall before symptoms begin.
• Keep indoor spaces bright during the day by opening curtains or sitting near windows.
• Prioritize physical activity and regular social engagement.
• Monitor your mood and energy levels throughout the year.
• Talk to your health care provider at the first sign of symptoms because early intervention can make treatment more effective.

If you notice a pattern of low mood or fatigue that returns each year, talk to your health care provider or a mental health specialist. Early diagnosis and treatment can help you manage symptoms and maintain emotional well-being throughout the year.

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