The presence and amount of clear vaginal discharge is definitely directly related to hormones. When hormones increase, the discharge increases and when hormones decrease, so does the discharge. This is what I've learned from my personal experience.
I did not have any vaginal discharge until after I was eighteen. I think my hormone levels started to increase at that time and I started to get thick, clear vaginal discharge on a daily basis.
And when I started taking antidepressants, my vaginal discharge decreased to almost nothing. When I stopped using antidepressants, the discharge returned. Antidepressants are said to decrease sexual desire, and based on its effects on vaginal discharge, I think it's true. I guess the medication affected my reproductive hormones.