St John's wort: Is it safe in bipolar disorder?

To the Editor,

St John’s wort (hypericum perforatum) is a herbal agent sold over the counter (OTC) in Australia and used to relieve mild depressive symptoms. It is generally regarded as being safe with few side effects. One complication increasingly being reported in the literature since 1998 was the emergence of mania in some individuals taking St John’s wort, with the mechanism not being clearly understood (Fahmi et al., 2002).

Our case is a 39-year-old man admitted for a manic episode following 4 weeks of overuse (twice recommended dosage of particular brand) of St John’s wort for a low mood. He had no past psychiatric history or genetic predisposition. He was not using illicit substances or concomitant antidepressants. His use of St John’s wort unmasked a Bipolar Disorder, and his mania resolved on cessation of St John’s wort and commencement of mood stabilizer medications.