Lack of light causes depression

Seasonal Affective Disorder (SAD) is a mood disorder associated with depression episodes and related to seasonal variations of light. People who develop this disorder suffer from depression during the winter months, with symptoms subsiding during the spring and summer months.

People, who suffer from this disorder, sleep a lot, overeat and put on weight. The lesser sunlight during these months disturbs the sleep-wake-cycle and may lead to SAD. People become irritable, depressive and start to avoid social interactions.

Most of the people will require help. The affliction is usually mild, but in severe cases may lead to suicidal tendencies. In very severe cases of SAD, antidepressant and psychotherapy treatment may become necessary.