Seasonal Affective Disorder (SAD) is a type of depression that occurs seasonally, typically during the fall and winter months when daylight hours are shorter. It's believed to be linked to reduced exposure to natural sunlight, which can disrupt the body's internal clock and affect mood-regulating neurotransmitters. Individuals with SAD often experience symptoms such as low energy, increased sleepiness, changes in appetite, weight gain, difficulty concentrating, and a general sense of sadness or hopelessness. SAD can significantly impact daily functioning and overall quality of life.