Just was browsing through this interesting site https://moodgym.anu.edu.au

Reasons that cause us to be anxious/depressed:

the need for approval from others  the need to be loved  the need to succeed  the need to be perfect  the sense of being able to influence/be responsible for other people's emotional reactions  happiness is contingent upon external things  the sense of feeling deserving

EDIT: Related to inner game stuff.