What is seasonal affective disorder?

Seasonal affective disorder (SAD) is a type of depression that's related to changes in seasons. SAD begins and ends at about the same time every year. 

Who gets seasonal affective disorder?

Seasonal affective disorder is more common in women than in men. Those who live farther north, where there are shorter daylight hours in the winter, are more likely to experience seasonal affective disorder. For example, people living in Alaska or New England may be more likely to develop SAD than people living in Florida. In most cases, seasonal affective disorder begins in young adulthood.

How does seasonal affective disorder affect your weight?

Like depression, seasonal affective disorder can impact different parts of your life, all of which can impact your weight. For example, some signs of seasonal affective disorder include loss of concentration or less interest in your regular activities. That could lead to less exercise, which can cause weight gain. Or depression can also cause cravings for foods that are high in fats and carbohydrates and low in nutritional value, which can increase weight. 

On the other hand, seasonal affective disorder and depression can have the opposite impact on some individuals. Nausea or a loss of appetite are also symptoms of SAD that could result in unintended weight loss. 

When does seasonal affective disorder occur?

If you're like most people with seasonal affective disorder, your symptoms start in the fall and continue into the winter months, sapping your energy and making you feel moody. Symptoms typically lessen during spring and summer.  

While less common, seasonal affective disorder can also occur in the period from spring to summer

What are the symptoms of seasonal affective disorder?

There are many symptoms of seasonal affective disorder. Each individual’s experience may differ, but the most common symptoms are: 

  • feeling depressed on most days
  • feeling worthless or hopeless
  • sadness
  • possible suicidal thoughts 
  • difficulty concentrating
  • reduced energy
  • trouble sleeping or oversleeping
  • weight loss or weight gain 

What causes seasonal affective disorder?

The exact cause of seasonal affective disorder is not known. Some factors that are believed to influence the condition include:

  • changes in the body’s internal clock due to seasonal changes
  • reduced levels of a certain chemical in the brain called serotonin
  • an imbalance in the hormone melatonin that influences sleep and mood patterns
  • vitamin D insufficiency  (when is the last time you had your levels checked by your primary care provider?)
  • gender – women are more prone to seasonal affective disorder
  • family history of seasonal affective disorder
  • personal history of clinical depression or bipolar disorder

How is seasonal affective disorder treated?

There are several treatments for seasonal affective disorder that have been found to improve its symptoms. 

  • Light therapy – This treatment is also known as phototherapy. It involves exposure to a bright light every day for people with seasonal affective disorder. This is intended to make up for less natural sunshine in the darker months. For this treatment, the person sits in front of a very bright light box every day for 30 to 45 minutes, usually first thing in the morning, from fall to spring. These light boxes, which are about 20 times brighter than ordinary indoor light, filter out the potentially damaging ultraviolet light, making this a safe treatment for most. However, individuals with certain eye diseases or taking some medications may have an increased sensitivity to sunlight. For these individuals, light therapy may not be appropriate, or must be done only under medical supervision.
  • Talk therapy – Also known as cognitive behavioral therapy, this treatment involves talking with a trained specialist who can work with you to help treat your seasonal affective disorder.
  • Medications – for some individuals, antidepressants or antianxiety medications may be helpful in treating seasonal affective disorder. 
  • Vitamin D therapyVitamin D is an important nutrient for our health and has wide-ranging effects, one of which includes boosting your mood. 
  • Alternative medicine – There are several forms of what is known as alternative medicine that can be helpful in treating seasonal affective disorder, such as acupuncture, reiki, and reflexology or hypnosis.
  • Healthy diet and exercise – The value of good nutrition and regular activity should not be underestimated. Eating well and moving more are not only good for your physical health, but your mental health as well. 

How can you prevent seasonal affective disorder?

While seasonal affective disorder may not be prevented, you can reduce your risk for it by focusing on habits that improve your mood and your overall well-being. Those include: 

  • eating a healthy, nutritious diet
  • monitoring your mood and energy levels and recognizing when you might need help
  • getting adequate rest and adopting good sleep hygiene habits
  • managing stress
  • avoiding alcohol
  • staying connected with family and friends to avoid loneliness

If you need help managing your weight, our Center for Weight and Wellness is here for you.

For more tips on well-being, visit the Being section of our Lifespan Living health and wellness blog.