Seasonal Affective Disorder (SAD) is a type of depression that occurs at specific times of the year, most commonly during the winter months when daylight hours are shorter. Symptoms may include feelings of sadness, fatigue, and changes in sleep or appetite. The exact cause is not fully understood, but it is believed to be related to changes in light exposure and its effect on the body's internal clock. Treatment options for SAD often include light therapy, which involves exposure to bright artificial light that mimics natural sunlight. Other approaches may include psychotherapy and medication, depending on the severity of the symptoms. Early intervention can help manage the condition effectively.