The yearly feeling of seasonal sadness and blues can affect your mood. Seasonal Affective Disorder is a type of depression that is associated with seasonal changes. It usually occurs during the winter but it applies to seasonal changes. Do you think you have a Seasonal Affective Disorder? If you are most likely to feel the symptoms of the Seasonal Affective Disorder, you will have a depressive feeling that starts in the summer and continues into the winter months giving you labile emotions.