Seasonal Affective Disorder (SAD) is a type of depression that typically occurs in a seasonal pattern, most commonly during the fall and winter months when daylight hours are shorter. It is believed to be linked to changes in light exposure, which can disrupt the body's internal clock and neurotransmitter levels. Symptoms of SAD include persistent sadness, low energy, irritability, difficulty concentrating, changes in appetite, and oversleeping.

Light therapy, psychotherapy, and medication are common treatments for SAD. Light therapy involves exposure to a special lightbox that mimics natural sunlight. Psychotherapy, particularly cognitive-behavioral therapy, can help individuals develop coping strategies. In some cases, antidepressant medication may be prescribed.

SAD can significantly impact daily life, but with proper diagnosis and management, individuals can alleviate symptoms and improve their well-being, especially as sunlight increases during spring and summer.