Seasonal Affective Disorder (Winter Depression / Blues)

There are many types of depression and various causes and triggers. A change in season may not seem like a possible cause of this serious mental health disorder but it can cause a type of depression known as seasonal affective disorder (SAD). Seasonal changes can also aggravate pre-existing depression and other mental health disorders.

What is Seasonal Affective Disorder?

Seasonal affective disorder (SAD) is a form of depression that arises with seasonal changes, usually during winter. It is also commonly referred to as winter depression or the winter blues. SAD is usually not a long term mental health problem. It starts and ends around the same time every year but this tends to coincide with winter and overlaps with fall (autumn).

The existence of seasonal affective disorder (SAD) has been and still is questioned. However, it still believed to be a very common syndrome. In the United States, seasonal affective disorder is estimated to affect as many as 1 in 10 people in certain regions. Women appear to be four times as likely to suffer with seasonal affective disorder than men.

Causes of Seasonal Affective Disorder

The exact cause of seasonal affective disorder (SAD) is not fully understood. It appears to be due to a combination of factors. Some of these factors genetic and therefore non-modifiable, while other factors are environmental and can be modified. It is important to note that seasonal affective disorder is more likely in northern countries during the fall and winter months.

Circadian Rhythm

The body’s circadian rhythm (biological clock) is directly affected by exposure to light, particularly sunlight. The sleep cycle in particular is influenced by light exposure. Towards the end of the day the levels of melatonin increases which coincides with the onset of darkness at night.

This hormone, melatonin, helps to induce and maintain sleep. However, the rise in melatonin may be affected with shorter days and longer nights that occur in fall and winter in particular. Therefore sleep patterns may be affected.

Vitamin D Deficiency

Vitamin D deficiency is also believed to play a significant role in seasonal affective disorder. The production of  vitamin is largely dependent on sunlight exposure. Dietary vitamin D comprises a smaller proportion of vitamin D in the human body. With decreased sunlight exposure, the levels of vitamin D gradually decreases.

Read more on benefits of vitamin D.


Although not conclusive, studies have shown some difference in the 5-HTTLPR gene and the 5-HT2A gene among people who are prone to seasonal affective disorder (SAD). Retinal sensitivity to light which could affect melanin secretion may also be an inherited factor.

Do Winter Blues Occur in Other Seasons?

Seasonal affective disorder (SAD) is a syndrome that occur with any seasonal change and not only in fall and winter. It tends to be more likely to occur in fall and winter but can occur in spring or summer. This is uncommon and may be more likely to occur in certain regions where spring and summer causes major shifts in environmental factors.

As with fall/winter blues, the reason why SAD may occur in spring and summer is unclear. Very long days, intense sunlight and possibly even high temperatures may be contributing factors. Spring and summer may also cause an aggravation of pre-existing mental health conditions like bipolar disorder.

Signs and Symptoms of SAD

Some people with seasonal affective disorder (SAD) have very mild symptoms, like low energy levels without any other noticeable symptoms. Seasonal affective disorder may not be immediately suspected as a possible diagnosis. Other people may have overt depressive symptoms and an aggravation of other pre-existing mental health symptoms.

The signs and symptoms seasonal affective disorder (SAD) includes:

  • Excessive sleeping or prolonged feelings of sleepiness.
  • Low energy levels with fatigue despite not being physically or mentally strained.
  • Lack of interest (apathy) in activities that were previously enjoyable.
  • Feelings of sadness that persist despite there being no clear cause/trigger.
  • Unexplained anxiety or agitation often with mood swings.
  • Problems with concentration and difficulty completing familiar tasks.
  • Unusual food cravings and appetite changes (usually increased appetite).
  • Weight gain, as a result of a high carbohydrate diet.

In severe cases, there may be other symptoms like feelings of worthlessness and guilt with thoughts of suicide. Seasonal affective disorder (SAD) in spring or summer months tends to be less severe and the opposite of some symptoms may appear, like insomnia instead of oversleeping or loss of appetite instead of an increased appetite.

Read more on signs of depression.

Treatment of Seasonal Affective Disorder

The treatment for seasonal affective disorder depends on several factors, such as the severity of the condition as well as the presence of pre-existing mental health diseases like bipolar disorder. It is important that seasonal affective disorder is diagnosed and assessed by a medical professional, preferably a psychiatrist, before treatment is commenced. Treatment options include:

  • Light therapy (phototherapy) involves exposure to bright light for a period of time on a daily basis, particularly after waking. It may only help for fall/winter blues.
  • Psychotherapy is an extensive set of therapies that are commonly referred to as counselling. Cognitive behavioral therapy is one type that may be helpful for SAD.
  • Medication may be prescribed for some cases of seasonal affective disorder. This usually involves the use of certain antidepressants which may used both for treatment and prevention.
  • Relaxation techniques may also be helpful in managing seasonal affective disorder. These practices may include yoga, meditation and other mind-body techniques.

Prevention of the Winter Blues

Some simple lifestyle measures can help to prevent seasonal affective disorder. These measures may not always be helpful for every person but should nevertheless be attempted, especially in people who tend to experience the winter blues on a regular basis.

Get as much sunlight as possible

Although sunlight exposure may be limited, it is important to maximize the amount and time of sunlight exposure. Open curtains and even windows if possible and try to spend as much times as possible near open windows. Bright artificial lights may also help but it is important to note that it lacks UV (ultraviolet) light which is available from sunlight and electric sources like tanning lights.

Spend more time outdoors

Apart from sunlight exposure, outdoor activities can also have other benefits such as the fresh air and providing a welcome distraction to prolonged indoor activities. A certain period of time should be dedicated to going outdoors on a daily basis. Walking around or even playing sport outdoors if possible should be considered.

Start an exercise program

The benefits of exercise for depression treatment, management and prevention are well known. Consider starting an exercise program or even opt to play a sport if possible. This should be outdoors preferably but indoor physical activity can also be beneficial. Always speak to a doctor before commencing with any exercise regimen.



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