What are symptoms you get with seasonal affective disorder?

Depression seasonal: The concept of sad is that some people are highly sensitive to the amount of uv radiation--daylight. When it goes below a certain threshold, they develop all the signs and symptoms of depression--down mood, decreased energy, sleep and appetitte changes, etc. This can be occur far north (or south) of the equator or in climates with lots of overcast days. Rx is a lightbox to lengthen uv exposure.

SAD: Seasonal affective disorder (also called sad) is a type of depression that occurs at the same time every year. If you're like most people with seasonal affective disorder, your symptoms start in the fall and may continue into the winter months, sapping your energy and making you feel moody. Less often, seasonal affective disorder causes depression in the spring or early summer.