Seasonal Affective Disorder is linked to what environmental factor?

• A. Sunlight exposure
• B. Heat exposure
• C. Humidity
• D. Wind

Answer: (A)

Sunlight exposure is the environmental factor linked to Seasonal Affective Disorder because this condition tends to appear in fall and winter when daylight hours are shorter. Fewer daylight hours disrupt the body's circadian rhythm and alter mood-regulating chemicals, increasing melatonin and lowering serotonin, which can lead to symptoms like low energy, sadness, and social withdrawal. Light exposure helps reset the circadian clock and can improve mood, which is why sunlight availability is central to SAD. Heat, humidity, and wind aren’t tied to the seasonal depth of mood changes seen in SAD and don’t drive the same biological shifts.