depression is difficult to address causally because it’s not a thing to have a cause. Depression is an absence of presence. Presence is the informing vital principle. Without presence, we cease to function, to BE, in form.
Attempting to assign causality to absence is trying to find the origin of space and attempting to fill it. All of it. Unwise in the extreme.
Instead, when experiencing what is referred to as depression, consider presence. Choose that which allows presence. Follow its lead and let it sculpt you.
Organ functionality and hormonal balance are but incidental aspects only obliquely related.
There are 2 states of existence, love and illusion. Love is alignment, illusion is not alignment. Choose.