Seasonal Affective Disorder
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Have you been feeling sad, irritable, or tired lately? Maybe noticing changes in your mood? It’s that time of the year again when many people struggle with Seasonal Affective Disorder, also known as SAD. SAD is a diagnosed medical condition, not just the “winter blues”.

What is SAD? 

SAD is a type of depression that follows a seasonal pattern usually beginning in the late fall and early winter and often lasting until spring and summer.

The seasonal pattern is thought to be caused by a lack of sunlight, so it occurs less frequently in the summer time. Sunlight helps the body to produce vitamin D, which helps regulate the activity of serotonin, our “feel-good” hormone.

Serotonin is a chemical messenger made in the body that helps regulate mood. People affected by SAD, or other depressive disorders, have a lack of serotonin, which causes symptoms associated with depression. Sunlight is also involved in regulating melatonin, a hormone in the body that helps with the body’s sleep-wake pattern. Increased levels of melatonin can cause feelings of fatigue, tiredness, and/or sleepiness, which are common symptoms of depression. Sunlight exposure helps to balance melatonin production, which can improve wakefulness and give you more energy during the day

Winter Blues vs. SAD
The “Winter Blues” is more common and may cause milder changes in mood, alertness, energy and appetite. It is not a diagnosed medical condition and does not require professional treatment whereas SAD does.


Who does it Affect?

SAD not only affects mood but also affects cognitive function, including concentration and memory. It is suggested that a person needs to experience SAD at least two years in a row to be diagnosed with the disorder. SAD commonly affects:

  • People who live in places with a cold winter season and farther away from the equator.
  • Night shift workers since they are not awake during the light hours of the day.
  • Research has shown that women are more prone to SAD symptoms and that there may be a genetic factor to the prevalence.

Seasonal Affective Disorder can range in severity of symptoms for everyone. Some individuals experience a milder form of SAD also known as Subsyndromal Seasonal Affective Disorder (S-SAD), where they may experience less frequent and less severe symptoms.   

The severity of symptoms, however can also be very debilitating to some individuals and can cause thoughts of harm or suicide. Some of the more common symptoms include:

  • Sad mood
  • Decreased energy levels
  • Changes in appetite
  • Difficulty concentrating
  • Withdrawn from social situations
  • Overeating


Treatment Options

There are treatment options that research has proven effective for those who experience S-SAD and SAD. The most common treatments include antidepressant medication, cognitive behavioural therapy (CBT) and light therapy.

Antidepressant medication can be prescribed and should be monitored by a medical professional. There are many different types of medications so it may take time to find one that works for you and it is important to remember they do not work for everyone. Antidepressants are designed to change the chemicals in the brain that affect mood and emotions. In high-risk populations, antidepressants can work to prevent winter depression.

Light therapy research has recently shown that it can be a successful option for preventing and treating Seasonal Affective Disorder and is generally well tolerated. Light therapy is administered through a “light box”, which releases ultraviolet light (UV) rays that mimic sunlight. Research recommends that 20-60 minutes per day of light exposure can reduce symptoms associated with SAD. Light therapy is simple, effective, and may cause fewer side effects (such as temporary headaches and irritability) compared to antidepressant therapy. Ensure that the light UV is 10,000 lux exposure (lux is a measure of light intensity).

Cognitive behavioural therapy can also be helpful as therapy sessions provide help and support for those with SAD. This type of therapy revolves around changing negative thought patterns that can contribute to depressive symptoms.

If you experience any of the associated symptoms or think you may be affected by SAD, it is important to talk to your doctor to determine which treatment options may work for you.

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