Studies have shown that kava-kava (sometimes just called 'kava') has helped treat some depression symptoms by increasing cheerfulness, having a calming effect and even work as a muscle relaxant. Depression and Kava. There has been some contention around the use of kava over the past decade, but this is mostly due to the fact that the direct source of many mass-produced supplements weren't rigorously regulated. Be sure you know where you get your herbs from! Challenge your practitioner(s) by asking to know where from they source their herbs.