Sometimes an event will bring it on, but other times it will not. There is also evidence that genetic and biochemical factors may play a role in the development of depression, but that role remains to be more thoroughly researched. Also, some people may be more prone to being depressed than others. When needs become excessive, extreme, or distorted, the behavior that is exhibited to fill them may be abnormal and depression producing. The role of events in a depression does not end with the event that brought on the depression.
Events can build on each other.
For instance, the depressed person may become increasingly irritable and have to stop working, which can further contribute to the depressed mood. Many experts believe that depression grows out of a combination of these factors. They say that the body chemistry of some people gives them the tendency toward depression, and then something in the life situation happens to trigger that depression. This triggering event is different in different people, but is often linked to some kind of loss, such as the loss of a loved one or of a job, or the loss of roots when people move or leave home for the first time. Signs of Depression Robert Fetsch, Colorado State University, states that depression is associated with many symptoms and not everyone has the same ones.