St John's Wort is as effective as many antidepressants and has fewer side effects. There are possible interactions causing serotonin syndrome if taken with antidepressants. Turmeric exerts both antianxiety and antidepressive effects along with its strong antiinflammatory effects. Sources
"The recommended dose of SJW is 300 mg three times per day of a standardized extract of 0.3% hypericin, for a total of 900 mg daily. Higher doses of 1,200 to 1,800 mg have been used successfully in more seriously depressed patients, with no increase in side effects" (Cass, 2003).