Seasonal Affective Disorder
Seasonal affective disorder (SAD) is a form of depression associated to changes in the seasons (often worse in the winter). Symptoms of SAD include mood swings, anxiety, withdrawal, disturbed sleep, lack of energy and loss of sex drive. Seasonal affective disorder is attributed to lack of daylight that prevents chemical production by the hypothalamus part of the brain. SAD sufferers have lower levels melatonin and serotonin chemicals that help regulate sleep, mood and appetite.