from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A form of depression occurring at certain seasons of the year, especially when the individual has less exposure to sunlight.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A form of depression associated with the lack of natural light during the winter months.
from the GNU version of the Collaborative International Dictionary of English
- n. A form of mild depression that occurs in winters, associated with reduction in the amount of sunlight. It is characterized by oversleeping, irritability, and sometimes overeating. It can be treated by light therapy and usually disappears with the arrival of spring.
Sorry, no etymologies found.
Light therapy has been used previously for people with significant seasonal affective disorder as well as nonseasonal depression.