Seasonal Affective Disorder (winter depression) Symptoms, Diagnosis and Treatments

Seasonal affective disorder (SAD) is another form of depression that manifests in a seasonal pattern. SAD is also called as “winter depression” because the symptoms are more severe and apparent during the winter season.

The symptoms of depression usually begin in autumn and are most severe during the months of December, January and February. SAD often disappears or improves during spring and summer, although it may come again in each winter in a repetitive manner.


The precise cause of SAD is still not known. Some factors that may play a role in its causation are:

  • Biological clock. Decreased sunlight in fall and winter may disturb the body’s internal clock (circadian rhythm) and lead to symptoms of depression.
  • Serotonin levels. Serotonin is a neurotransmitter which regulates mood. Reduced sunlight can cause a drop in levels of serotonin that may cause depressive symptoms.
  • Melatonin levels. Melatonin is a hormone which regulates mood and sleep patterns. Change in the season may disturb the balance of melatonin in the body, which can trigger depression.

Risk factors:

Factors which can increase the risk of SAD are:

  • Age. Young people are more prone to SAD
  • Sex. SAD is detected more often in females than in males. However, symptoms may be more severe in males.
  • Family history. Having a family history of SAD or some other form of depression increases the risk.
  • Clinical depression. If the person already has depression, then the symptoms may worsen seasonally.
  • Place of living. SAD is more commonly seen among people who live far north or south of the equator. It happens because of the prolonged winter season and shorter summer days.

Seasonal affective disorder or winter depression


Symptoms of SAD may include:

  • Persistent low mood and sadness
  • Loss of interest in everyday activities
  • Irritability and frustration
  • Feelings of guilt, despair and hopelessness
  • Agitation and anxiety
  • Lack of energy and sleepiness during daytime
  • Sleeping for long hours than usual
  • Overeating
  • Weight gain
  • Having frequent thoughts of death


A doctor diagnoses SAD through thorough evaluation which may include:

Physical examination. The doctor asks questions about medical and family history and does a proper physical examination.

Psychological evaluation. The doctor may ask about your thoughts, feelings and behaviour patterns. He may also ask you to answer a questionnaire to help him detect the symptoms of SAD.

Lab tests. The doctor may advise certain tests to rule out any other health problems like diabetes or thyroid.


Treatment of SAD includes medications, light therapy and psychotherapy.


Doctor usually recommends anti-depressants for the treatment of SAD, especially when the symptoms are severe. An extended-release version of anti-depressants is used to prevent depressive episodes in people with a history of SAD.

The doctor may advise starting the treatment before the symptoms begin each year and may also ask you to continue the treatment beyond the time the symptoms typically subside.

Light therapy

Light therapy also called as phototherapy, is one of the first treatments recommended for Fall-onset SAD. It usually starts working in few days and may not cause any side effect. Not much research has been done about light therapy. However, it appears to be effective in treating people with SAD.

In this therapy, a person has to sit at a distance from a special light therapy box so that he/she is exposed to bright light. This light mimics natural outdoor light and may cause changes in the brain chemicals linked to mood.


Another option to treat SAD is psychotherapy or talk therapy. It may help to:

  • Learn coping skills to manage SAD
  • Identify negative thoughts that may be making the symptoms worse
  • Learn how to manage stress


In addition to the above treatment plans, the doctor may recommend some lifestyle modifications like:

Changing your environment. Open windows and doors so that maximum natural light can come inside. Sit in the light or closer to windows so that you are exposed to bright light, while at home or the office.

Going outside. Take a walk, have lunch in open spaces or simply sit or stroll in a park to soak up in the sun. Even in the winter season, outdoor natural light helps especially if you spend time outside within one-two hours of waking up.

Exercising. Many studies have proved that exercise helps in reducing stress and anxiety, which helps in relieving the symptoms of SAD. Regular exercise keeps you fit and makes you feel better about yourself.

Socialising. You should try to connect with other people or join some group activities. Socialising helps in sharing your thoughts and lifts your mood. It also acts as a distraction from daily depressive symptoms.

Going for a trip. If possible, go for a trip to a warm sunny place in winters or cooler locations in summers.


There is no one certain way to prevent the development of SAD. However, if you start early and take steps to manage depression, you may be able to prevent the symptoms from getting worse. It may be beneficial to begin treatment before the onset of symptoms in winters and then continue the treatment beyond the time symptoms usually disappear. Some people may require continuous treatment to prevent worsening of symptoms.


If left untreated SAD can get worse and may lead to:

  • Social withdrawal
  • Suicidal thoughts and behaviour
  • Substance abuse

When to consult a doctor?

It is very normal to feel low or down on some days of the year. However, if you are feeling low for many days in a stretch and you don’t feel motivated to do activities you usually enjoy, you need to see your doctor. Also, if your sleep patterns are getting disturbed, appetite has changed, you feel hopeless, or you are thinking about death or suicide, then it is crucial to consult a doctor as soon as possible.

Consult a top Psychiatrist

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  • Seasonal affective disorder (SAD). http://www.nhs.uk/Conditions/Seasonal-affective-disorder/Pages/Introduction.aspx. Accessed on 29th Sept 2016.
  • Seasonal affective disorder. https://medlineplus.gov/seasonalaffectivedisorder.html. Accessed on 29th Sept 2016.
  • Seasonal affective disorder. http://www.mind.org.uk/information-support/types-of-mental-health-problems/seasonal-affective-disorder-sad/#.V-nxrvB97IU. Accessed on 29th Sept 2016.

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