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.

This case adds to existing literature on the emergence of mania related to St John’s wort use. Given the accumulated evidence over 17 years of similar cases, it is surprising that there are no warnings on the bottles or in the product information (PI) of this potential complication. The authors also found that there was no consistency across different brands in concentration of the active ingredient, hypericin, and there has not been any thorough research into therapeutic dosages and evidence base for major depression (Mitchell, 1999).

It is interesting to note that on January 1st, 2000, Ireland banned OTC sale of St John’s wort and made it a prescription-only medication, due mainly to concerns related to potentially serious herb–drug interactions (McIntyre, 2000). Our case and other published reports suggest that the Australian Regulatory Guidelines for Complementary Medicines might need to consider changes in the content, labelling and marketing of St John’s wort to warn about such potential risks, including possible emergence of mania. The authors would like to propose that St John’s wort be moved off the shelves and placed behind the pharmacist counter, so that appropriate psychoeducation can occur by Pharmacists prior to purchase. Importantly, general practitioners, pharmacists and other health professionals should also receive education about St John’s wort’s potential to induce mania in vulnerable individuals. The use of St John’s wort in Bipolar depression has not been extensively studied. Given the potential risk of treatment-emergent mania with St John’s wort use, the authors do not recommend its use in Bipolar Disorder.