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Seasonal Affective Disorder (SAD)

258 days ago / by Siddu G / 6 mins read

Does your mood change with the changes in the seasons? Does summer heat cripple you? Do the cold winter months deflate your moods? If so, you may be having seasonal affective disorder (SAD).

Seasonal depression is a mood disorder that gets triggered when season changes. It happens every year at the same time, usually beginning in fall or winter and ending in spring or early summer. In winters, nights are long and cold and sometimes days go by without sunshine. You may feel the winter blues, being stuck inside. This resolves once spring sets in.

Summer Depression and India

‘Summer depression’ is a rare form of seasonal depression that starts in late spring or early summer and ends in fall. In India, seasonal depression is more prevalent in the hot, summer months. Summer SAD accounts for only 10% of all SAD cases but studies have shown that in India, its actually more prevalent than regular SAD. In the hotter regions of our country, summer depression is common. In India alone, more than 10 million people experience similar symptoms of seasonal affective disorder. It should not be taken lightly as people with SAD are just as ill as people with major depression, according to psychiatrists.  

What causes seasonal affective disorder (SAD)

Though there is not much clarity on why seasonal depression occurs, the lack of sunlight is a major trigger for it. Seasonal affective disorder may be caused due to various reasons. A few of these are-

Shift in Circadian rhythm- as seasons change, people experience a shift in their circadian rhythm or biological clock that can shift their regular routine. Circadian rhythm is responsible for regulating our moods, sleep and hormones. When it changes, people may have trouble regulating their moods.

Chemical imbalance in the brain- neurotransmitters, our brain chemicals send communications between nerves. Two specific brain chemicals, melatonin and serotonin may be responsible for SAD. When the days are shorter and there’s less sunlight, melatonin which is linked to sleep increases and our serotonin levels responsible for our feelings of happiness decreases.  Serotonin production goes up when exposed to sunlight. Less sunshine in dark, winter days can cause low levels of serotonin leading to depression. 

Vitamin D deficiency– low dose of sunlight also means low vitamin D since sunlight helps produce vitamin D. This change can affect serotonin and mood.

Family history– people whose family members have a history of depression are at greater risk for SAD. 

Symptoms of SAD

Seasonal affective disorder is considered a type of depression occurring because of the change in season, with symptoms lasting for about 4 to 5 months in a year.  The signs and symptoms therefore are similar to those associated with major depression, and some specific symptoms that differ for winter SAD and summer SAD. It Is not necessary that a person with SAD will experience all of the symptoms listed below.

Symptoms of SAD may include:

  • Feeling of depression almost everyday
  • Lack of interest in daily activities
  • Experiencing changes in appetite and weight
  • Not getting adequate sleep
  • Feeling tired and agitated
  • Having low energy
  • Lacking concentration
  • Feeling of guilt, worthlessness or hopelessness
  • Having suicidal thoughts

SAD in the winter months comes with its added symptoms

  • Over sleeping
  • Over eating and carbohydrate cravings
  • Weight gain
  • Social withdrawal

Summer month SAD symptoms include-

  • Insomnia
  • Lack of appetite
  • Weight loss
  • Restlessness and agitation
  • Anxiety
  • Rash and violent behavior


Consult a health care practitioner if your mood and behavior shift along with the calendar. They may advise certain tests and ask specific questions to determine if your symptoms are that of SAD. Tiredness, fatigue and low energy could be a sign of another medical condition called hypothyroidism or hypoglycemia so doctors may ask for a thyroid test. If your symptoms of depression are more frequent in particular seasons than other depressive episodes that you may have had during your lifetime, chances are, you have SAD.

Treatment for SAD 

SAD can be treated with counselling and therapy. There are also other treatments available to treat SAD. –

Light therapy– since lack of sunlight is a major cause for seasonal depression, one of the treatments include increased exposure to light during winter months. Light therapy involves sitting in front of a light box that emits a very bright light (filtering out harmful UV rays) for about twenty minutes every day, usually in the mornings.  This therapy is generally advised through the winters until enough sunlight is available outdoors. Symptoms tend to get better within a few days or sometimes within a few weeks. But this should strictly be taken under medical supervision. If the UV light is not administered properly, it may cause adverse reactions like eye and skin issues. While the side effects are minimal, a patient with a history of bipolar disorder must tread with caution while taking light therapy.

Cognitive Behaviour Therapy or Talk Therapy– CBT focuses on replacing negative thoughts and feelings associated with depression with more positive thoughts. CBT helps the patient ease the sense of isolation and loneliness that a person suffering from SAD often feels. The support and guidance of a professional therapist helps the patient to understand their condition as well as learn to prevent and minimize future bouts of seasonal depression.  Research has shown that CBT produces the longest – lasting effects in the treatment of SAD

Medications- Medicines that help to regulate the balance of serotonin and melatonin in the brain that affect mood and energy may be advised by the doctors. Antidepressant medications called selective serotonin reuptake inhibitors (SSRIs) are the common medicines advised. Talk to your doctor before starting these medicines.  

Vitamin D- lack of vitamin D, which is dependent on sunlight affects our moods and may lead to depression. Doctors may advise vitamin D supplement to combat the deficiency.

Spend time outdoors– doctors often advise patients to spend more and more time outdoors, exercising and indulging in physical activities to uplift mood, get little sunshine and help alleviate the symptoms of SAD.

How do you prevent SAD?

Spending some time outside everyday helps in preventing SAD. Exercising, eating a well-balanced diet, keeping yourself well hydrated are other ways of making sure you do not let seasonal depression get the better of you. Talking to your friends or family always helps.If the symptoms of depression, fatigue and mood swings persist, reach out to a doctor.  At, we have super specialist doctors who will help you understand SAD and treat it with compassion and empathy. All you need to do is click on for a hassle-free appointment with our experienced doctor and you will soon be on your way to recovery. Our specialists include Dr Soumya Hegde, Dr Tanya Machado, Dr Sulata Shenoy, Dr Vyjayanthi Bonanthaya, and Dr Sujai Subramanian.

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