hey pruni
I took SJW about 6 months ago after it was suggested it might help with PMT. I was advised to take the tincture (from Holland and Barrett) - just had to put a few drops into water either once or twice a day.
Tbh, I wasn't depressed when I took it so I don't know if that affected the way it made me feel - but it really made me feel much much worse at first. I felt completely hyper - almost like a buzzing in my brain. I took it for a number of weeks and that feeling never went away (almost like being permanently on edge) but once I stopped taking it, I did feel like I was in a better state of mind than before I took it (iyswim).
I think it works much like some of the other milder antids in that you may not see the positive effects for a couple of weeks so don't lose hope. Also, for some people, I think it can, initially, make them feel worse so if it does that to you, it might be worth considering a chat to the GP.
Hope you are ok xx