ESSAY

Most people think that the happiness depends on how you are, your personality. They have some strongs points reasons to think it that because as it’s well known that the DNA of each person interferes with the personality, like there are people who are prone to have depression. However it can be changed with a different style of life (or a different lifestyle).
Firstly, it your health is very important your health. Having a balanced diet and doing physical activity, are two pillars to be happy. As well Also it is important your feelings are important, how you feel mentally. It helps to be better when you have close friends or family who you can support depend on (or friends and family who can support you)
Secondly, the money is very important. It’s a contradictory point. Lots of people say you can be happy without money, but the true truth is the that life is based on money. If there is no money, there isn’t a balanced diet, or healthy habits.
To conclude, I believe that the personality is very important to be happy or not. Nevertheless if these people change your their style of life, I think they would be happier.

Very good! My corrections are in red and my suggestions to sound more natural are in blue/grey.

You can say "because it's well known" or "as it's well known" but not "because as..."