I shouldn't be stuck here but I seem to be. I can't seem to get to the upper levels of the asylum. I can see some of the catwalks above me or across from places I can get to but I can't seem to find a way up to them. Can anyone give some guidance?

...I gathered as many crates and barrels as I could find in the vicinity and set up a makeshift staircase...not as worthwhile as it felt upon making it to the top, the reward being a couple of chests with mundane contents...