You should always pray to attain the level that is hidden from you. And when it is revealed, you should pray to achieve the level that is still hidden. This is how to rise from level to level. It is the way to find joy, which is the source of spiritual strength. You need to be strong in order to draw closer to the true Tzaddikim.
Depression is a form of idolatry.
How joyous we are depends on our purity and how close we are to the true Tzaddikim, who are the joy of all Israel. Through carrying out the mitzvoth in joy it is possible to reach the ultimate goal of all things. The joy of the mitzvot is the perfection of holiness. It has the power to free all the vitality and holiness which have been caught in the husks and to elevate them. The root of depression is in the husks, which are at war with all that is holy.