What is SAD? A mental disorder triggered by winter

New Delhi,UPDATED: 21 December 2022 15:20 IST

Author: Daphne Clarence: There are many behavioral and mental changes that winter affects. Limited sun exposure, dim lighting, and gloomy weather can produce neurotransmitters like serotonin in the brain that are associated with a person’s mood.

In the autumn or winter season, with less exposure to natural light, seasonal affective disorder (SAD) can be experienced. This is a type of mental disorder, a subset of depression, that comes and goes in a seasonal pattern. Sometimes known as winter depression, SAD can worsen as the seasons progress.


Seasonal affective disorder or SAD, also known as seasonal depression, is the seasonal part of major depressive disorder (MDD) caused by seasonal changes. Symptoms of this mental disorder first appear in winter.

This condition occurs primarily in women and young adults, according to Healthline.com. One of the contributing factors in SAD is thought to be light. One theory suggests that decreased exposure to sunlight in winter and increased exposure in seasons such as spring and summer may affect the body’s natural biological clock, regulating hormones, sleep and mood. People with SAD may have difficulty regulating their circadian rhythm (sleep-wake cycle).

According to Dr. Richard S Schwartz, Associate Professor of Psychiatry at Harvard Medical School, special receptors in the retina (the light-sensitive part of the eye) transmit information about the light in our environment to the brain’s master body clock, known as as a suprachiasmatic nucleus.

As a result of an altered sleep cycle caused by light, neurotransmitters such as melatonin and serotonin can be affected. Serotonin is related to mood, and melatonin affects sleep patterns.


The symptoms of SAD are similar to depression, but occur in the late fall and early winter.

  • Persistent low mood
  • Loss of interest in daily activities
  • Feelings of hopelessness, guilt, and worthlessness
  • Feeling lethargic
  • Feeling sleepy during the day or sleeping more than usual
  • Carbohydrate cravings and weight gain


Anyone experiencing prolonged symptoms of SAD should visit a doctor or mental health professional. A common treatment for SAD is cognitive behavioral therapy (CBD), which will help a person learn to focus on positive thoughts. Antidepressants and vitamin D supplements, based on professional consultation, can help in this case.

Another treatment may be light therapy. In this, a person has to sit in front of a do-it-yourself box every morning for about 30 minutes after waking up. “For seasonal and seasonal depression, the effectiveness of light therapy is similar to that of antidepressant medication or popular forms of psychotherapy such as cognitive behavioral therapy,” said Dr. Richard S Schwartz.

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