Depressor.
Depressive.
The act of depressing, or the state of being depressed; low spirits or vitality; dejection; melancholy.
That which is depressed; a low or hollow place.
At home there was more surface depression. – The Amazing Interlude by Mary Roberts Rinehart
In the thought of the former we see expressed nothing but profound depression, fear and selfishness. – Thought-Forms by Annie Besant C.W. Leadbeater