What is Seasonal Affective Disorder? Why it happens in winter?

Written By Shweta Singh | Updated: Oct 31, 2024, 05:06 PM IST

Common SAD symptoms include hopelessness, loss of interest in daily activities, fatigue, trouble focusing, and changes in sleep and appetite.

Seasonal Affective Disorder, or SAD, is a type of depression that appears at the same time every year, usually in the colder months. Often known as the winter blues, SAD impacts mood, energy levels, and overall mental well-being. While it commonly occurs in winter, a less frequent form also exists in summer. This condition is closely linked to reduced sunlight exposure, which significantly affects brain chemistry and sleep patterns.

SAD primarily occurs due to the body’s reaction to limited daylight. The lack of sunlight influences the body’s circadian rhythm, which is an internal clock that regulates sleep and mood. As days shorten, the circadian rhythm can become disrupted, leading to feelings of fatigue and depression. This effect is intensified in winter when natural light exposure is minimal.

A hormone imbalance caused by reduced sunlight also plays a key role. Serotonin, the hormone associated with mood, decreases due to the lack of sunlight, causing sadness and irritability. Meanwhile, melatonin production increases with prolonged darkness, leading to sleepiness and a drop in motivation. Together, these hormonal shifts result in symptoms like lethargy, excessive sleep, and a general feeling of low energy.

Common SAD symptoms include hopelessness, loss of interest in daily activities, fatigue, trouble focusing, and changes in sleep and appetite. Cravings for carbohydrates, weight gain, and a feeling of heaviness in the limbs often occur. In severe cases, SAD can bring about thoughts of suicide.

Winter tends to worsen SAD symptoms because of shorter days, lower temperatures, and more cloud cover, all of which reduce sunlight exposure. SAD impacts various groups but is especially prevalent among women, children, and the elderly.

Fortunately, SAD can be treated through light therapy, which imitates natural sunlight, and Cognitive Behavioral Therapy, which helps manage negative thought patterns. Making lifestyle adjustments like spending time outdoors, staying active, and eating a balanced diet can also ease symptoms. Early recognition and treatment can significantly improve quality of life, helping those with SAD better manage the challenges of the colder months.