These symptoms tend to worsen over the winter months and then remit around March or April. In addition to the restricted seasonal recurrence, symptoms of WD include altered sleep pattern with increased sleep overall, decreased activity and increased appetite.
Mood changes can range from apathy to significant depression with suicidal ideation.
Winter Depression may be superimposed on a Major Depressive Disorder, in which case patients remain stable on medication through the summer months but experience breakthrough depression in fall and winter. We believe the increased incidence of winter depression experienced in the Northwest results from the dramatic decrease in daylength we experience during the winter months. The reduction in daylight hours, desynchronizes the body clock, disturbing our circadian rhythms. This desynchronization results in the symptoms of Winter Depression. It's the short winter days, therefore, and not the perpetually overcast skies, that are responsible for Winter Depression.