As early as 1989, the United Nations World Health Organization (WHO) made a new definition of health, that is, "health is not only the absence of disease, but also physical health, mental health, good social adaptation and moral health". Depression and anxiety are two common mental disorders that affect mental health, among which depression has become the fourth largest disease in the world.
The purpose of the World Health Organization is to enable people all over the world to achieve the highest possible health level. The main functions of the World Health Organization include: promoting the prevention and treatment of epidemic and endemic diseases; To provide and improve teaching and training in public health, disease treatment and related affairs; Promote the determination of international standards for biological products.