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.
It is so great that you have posted this info about seasonal affective disorder (SAD). My friend is suffering from it and for quite some time we are informing our friends and all people that we know about it. It seems that most of them have never heard of it but we all agree about one thing and that is that during the spring and summer we are all happier and somehow prone to positive thinking.
Also they have said that during the holidays we all get a little bit depressed and mostly married couples which is weird. I always thought that single people are more sensitive during this period of year.
Once again thank you for posting this.