What is seasonal affective disorder?
Feb 11, 2023
Source: Cainiu Health
Dr. Zhu Gang
Introduction
Seasonal affective disorder (SAD) is a mood or emotional disturbance that typically occurs in late autumn and winter. Most individuals with SAD are in good health for much of the year, but experience depressive symptoms during seasons when days become shorter and nights longer, with women being more commonly affected. Seasonal affective disorder is primarily caused by increased levels of certain hormones.
Seasonal affective disorder (SAD) is a type of mood or emotional disturbance that typically occurs in late autumn and winter. Most individuals with SAD remain in good health for much of the year, but begin to experience depressive symptoms during seasons when days become shorter and nights longer, and it is more common in women.
SAD is primarily caused by increased hormone levels. In the human brain, there is a small gland called the pineal gland, which secretes a substance known as melatonin. Melatonin acts on the brain not only to induce sleep but also to cause low mood and slowed thinking. Bright light can suppress or reduce melatonin secretion, helping to alleviate feelings of depression. Due to seasonal changes and reduced sunlight exposure, melatonin secretion increases, leading to the development of seasonal affective disorder.
In clinical practice, light therapy is commonly used, in which patients are exposed to higher levels of light according to specific requirements regarding brightness and duration. This treatment is highly effective in reducing symptoms. When combined with medications such as serotonin (5-hydroxytryptamine), it can also yield beneficial results.
