Many time depression is not the root of the problem. It can be a symptom of
other problems: such as hypothyroid, lack of hormones, inadequate nutrition.
There are things that people can do to avoid depression: stay off of sugar, get
hormones regulated, eat nutritiously every day (green smoothies help a lot), get
plenty of sleep every day. However, these things don't work for all kinds
of depression. But they very definitely help many people.