Honestly, that is not entirely known.
Some has known causes related to external events, but much of it has far more complex internal (e.g. psychological, neurological, biochemical) causes that are not yet understood.
depression
depression
DEPRESSION
depression
Gold.
false
Depression is not only a common mental disorder, but one of the single most common. Somewhere around one in five men suffer from depression, and one in three women.
Jobs
false
Depression can have such organic causes as infections if the brain becomes involved, but no there is nomicroorganism that causes depression.
The most popular belief of the cause of the Great Depression is the stock market crash of 1929. Economist still debate about the other causes. Excess speculation in the stock markets added to the causes of the depression.
Some of the most common causes of bleeding gums is lack of flossing and gingivitis.