What Is Seasonal Affective Disorder (SAD) And What Causes It?

The holidays are a time of great joy for many people. But for many, they are also a time of great sadness. Seasonal depression, or SAD, is a type of depression that’s triggered by changes in seasons. People who suffer from SAD experience symptoms similar to those of major depression. But SAD is less severe and shorter-lived. While SAD is most common in fall and winter, people in the northern hemisphere can also experience SAD in the summer, when days get shorter and nights get longer.

SAD is diagnosed when patients experience at least two of the following symptoms for at least two consecutive weeks: depressed mood, loss of interest in activities, trouble sleeping, weight gain or loss, fatigue, or feelings of worthlessness or guilt. SAD usually begins in the late fall or winter, but there have been cases reported as early as September and as late as April. Although the cause is not known, SAD has been linked to changes in the seasons, which can be linked to a lack of exposure to sunlight.

Experts believe that SAD occurs when light triggers changes in brain chemicals, causing symptoms of depression. Because SAD has a seasonal pattern, many experts believe that taking steps to help control SAD can help to prevent it. Light therapy is the most common treatment for SAD.

Lightboxes are a type of light therapy that emits bright light and provides therapy for several hours each day, for 30 to 45 minutes. Light therapy should be used in conjunction with antidepressant medication, which can also help to improve symptoms. Exercise can also help to improve symptoms. Exercise may be especially helpful for people who work indoors and spend most of the day sitting, as most people do. Certain foods can also help to improve symptoms, such as certain omega-3 fats and foods high in serotonin.