Seasonal Affective Disorder (SAD)

Information on the causes and symptoms of seasonal affective disorder and seasonal depression.

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  1. What is Seasonal Affective Disorder?
  2. Diagnosing Seasonal Affective Disorder
  3. What Causes Seasonal Affective Disorder?
  4. Help for Seasonal Affective Disorder
  5. More Info on Seasonal Affective Disorder

What is Seasonal Affective Disorder?

When the weather is sunny and bright people tend to feel more upbeat and positive. When the weather is gloomy, cold and dismal, moods tend to slump and often people feel a little down.

However, for certain individuals these mood shifts develop into a type of depression that accompanies seasonal changes and affects their ability to function normally. Recurrent episodes of clinical depression that surface during seasonal changes, particularly winter, are referred to as Seasonal Affective Disorder (SAD).

This condition is caused by a biochemical imbalance in the hypothalamus – the part of the brain that governs the primary functions of the body such as appetite, temperature, sleep, sex drive, mood and activity.

The hypothalamus is stimulated by natural light entering the eye and striking the retina. When the days are short and sunlight is reduced, the hypothalamus has to adjust its response to the various body mechanisms, slowing down these functions.

What is Winter Depression?

A milder form of this type of depression is more commonly referred to as winter depression, winter blues, cabin fever or hibernation reaction. While winter depression can be uncomfortable, the condition is not unbearable.

The classic symptoms of winter depression include fatigue, oversleeping, carbohydrate craving, weight gain, lack of sex drive, and sometimes even hopelessness, social withdrawal and suicidal thoughts. These symptoms are similar to those of SAD - Seasonal Affective Disorder – but not as severe.

Winter depression usually begins in late fall or early winter and generally disappears by the summer (begins in October or November and subsides in March or April). It frequently affects people living in the northern geographic regions. People with winter depression are affected by the changes in environmental light such as overcast weather or dim lighting which worsens their depression.

Winter is not the only season responsible for mood slumps - a less common type of Seasonal Affective disorder is called summer depression and it usually begins in late spring or early summer and goes away by winter.

Diagnosing Seasonal Affective Disorder

Very often SAD is difficult to diagnose because the symptoms presented are so similar to other types of depression. It is sometimes misdiagnosed as a physical condition such as hypoglycemia, hypothyroidism, infectious mononucleosis, and other viral infections.

The diagnosis for SAD is based upon the reported symptoms, along with a history of seasonal episodes. A Seasonal Assessment Questionnaire (SAQ) will also determine:

  • Sleep patterns
  • Weight changes
  • Energy levels
  • Mood changes
  • Social activity
Common symptoms of Seasonal Affective Disorder
  • Weight gain
  • A change in appetite (carbohydrate and sweet craving)
  • A heavy feeling in the arms or legs
  • Physical ailments such as body aches, constipation, diarrhea
  • Low energy levels
  • Fatigue
  • A tendency to sleep for longer periods
  • Loss of sex drive
  • Difficulty concentrating
  • Irritability and anxiety
  • Hopelessness
  • Suicidal thoughts
  • Crying spells
  • Increased sensitivity to social rejection
  • Social withdrawal

Common symptoms of Summer Depression include the following:

  • Poor appetite
  • Weight loss
  • Sleep Disorders (such as Insomnia)
  • Irritability
  • Crying spells
  • Trouble concentrating

SAD affects approximately half a million people in the United States. It is more common in women than in men. People living in the northern and southern hemisphere are also affected, although SAD is more common in the northern geographic countries where the winter day is shorter. This disorder tends to begin in people between the age of 20 and 40. It may also affect children and teenagers. The risk of SAD decreases as adults become older.

What Causes Seasonal Affective Disorder?

The exact causes of SAD are unknown. Research shows that a lack of bright light during the winter months may be the cause of the development of symptoms of seasonal affective disorder - bright light affects the chemicals in the brain.

Other research shows that a disrupted body clock (circadian rhythm) causes depression and lethargy. In addition, low serotonin (neurotransmitters carrying messages to the brain) and melatonin levels (the hormone which makes us sleep) can be found in people suffering from SAD.

Help for Seasonal Affective Disorder

In many cases, people who experience symptoms of seasonal affective disorder are often misdiagnosed because they symptoms are varied and common to other ailments. However, there are effective ways to treat and control SAD and it is not necessary for people to suffer year after year.

Symptoms of seasonal affective disorder associated with depression can affect daily living and should not be ignored. If you are wondering how to beat seasonal depression; treatment options include conventional therapy, psychotherapy, complementary therapy, natural therapy or a combination of these approaches.

Treatment Options for SAD

Conventional Therapy

Conventional drugs for the treatment of SAD include antidepressant medication such as Prozac, Zoloft, Paxil or Celexa. While these may be beneficial in the short term, many long term effects are unknown.

In addition, side effects often include insomnia, reduced sex drive, weightgain, headaches and other symptoms, while withdrawal symptoms when stopping these drugs are frequently reported.


Counseling and cognitive-behavioral therapy can be very helpful and provide support during the difficult months as well as help with lifestyle changes.

Complementary Therapy

  • Light therapy (phototherapy) requires you to sit in front of a light box or special lamp that is 10 to 20 times brighter than ordinary indoor lights for approximately 30 minutes each day.
  • Massage
  • Diet rich in fruit and vegetables

More Information on Seasonal Affective Disorder

Tips for Coping with Seasonal Affective Disorder

If you are wondering how to beat seasonal depression, here are some tips to help you cope with Seasonal Affective Disorder:

  • Allow more natural sunlight into your day by spending time outdoors, keeping the curtains or blinds open and decorating your space with bright, cheerful colors
  • Eat a well balanced diet
  • Exercise regularly, specifically outdoors if possible, by jogging, walking, cycling or playing golf. Studies have shown that one hour in the winter sunlight can lift your spirits
  • Take a winter vacation in a sunny location
  • Stop negative thoughts and try to develop a positive outlook that you are going to enjoy winter
  • Incorporate more laughter into your life – it is said to release the chemical, dopamine into the brain which counteracts SAD
  • Surround yourself with supportive friends and family
  • Minimize stress by practicing deep breathing exercises, meditation, yoga or pilates
  • Do things you enjoy such as reading, listening to music, shopping, painting or cooking
  • Seek counseling or psychotherapy
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