Definition:
Diurnal mood variation is a symptom of depression typically characterized by feeling worse in the morning, but better as the day progresses. This symptom usually is associated with more severe or melancholic depression.
It is not known what causes diurnal mood variation, but it is thought to be related to be related somehow to our body's circadian rhythm, which is a natural pattern of variations in wakefulness, body temperature, blood pressure and hormonal secretion that the body progresses through during the course of a 24-hour day.
