"Will the room look too small? Will I feel like the walls are closing in? Will it be depressing?"
The answer is: no, no and no. Not if it's done right and well balanced with other elements in the room.
To prove my point, I am showcasing rooms with the darkest paint possible: BLACK! I dare say, you will find these rooms chic and elegant -- never dull or depressing.
So, are you still afraid of the dark?