seasonal affective disorder

Definitions

Medical

  • noun a condition in which a person becomes depressed and anxious during the winter when there are fewer hours of daylight. Its precise cause is not known, but it is thought that the shortage of daylight may provoke a reaction between various hormones and neurotransmitters in the brain.
  • acronymSAD
http://www.dictionarycentral.com/definition/seasonal-affective-disorder.html