Press Release
6th October 2001
St John's Wort and SAD
St John's Wort (SJW) is a herbal remedy, which has been used since medieval times to treat mild depression. It has gained popularity in recent years but although some clinical trials have taken place, mostly in Germany, evidence as to its safety and effectiveness as a treatment for SAD is limited.
SADA has been concerned for some years about the widespread advertising for SJW products, which are sold in the UK as OTC (over the counter) remedies, not on prescription. Until recently, little has been published on the potential side effects and drug interactions of SJW.
Regulation of OTC medicines is, in SADA's view, very lax. Prescription medicines have to pass many years of stringent trials before being launched but OTC remedies do not.
Many SAD sufferers have tried SJW in recent years and SADA has heard many different reactions; some, very positive but others ranging from negative to disastrous, with side effects causing lasting health problems.
SADA was made aware (alas, not by the companies marketing SJW products) that SJW interacts with bright light and can cause negative symptoms of photosensitivity (sensitivity to light). As the principal clinically-proven treatment for SAD is bright light, this news was potentially alarming.
Early in 2000, several media reports stated that SJW had been found to interact negatively with a number of widely used prescription medications. The Department of Health issued a communication, CEM/CMO/2000/04 listing these medications and warned of the possible dangers.
As no clinical trials of SJW in SAD have been undertaken in the UK, SADA decided to conduct a survey amongst its membership of 2000 SAD sufferers to assess the perceived value of SJW as a treatment for SAD. In May, 2000 questionnaires were sent to SADA members: 308 were returned and 291 were accepted for analysis – a return rate of 15%.
- Two thirds of respondents (c 200) had tried SJW, of whom 70% combined it with bright light treatment and 16% with antidepressant medication, over an average period of use of 18 weeks.
- Just over 40% of users thought it effective or mostly effective.
- Just over 30% reported adverse effects, most commonly headaches (13%), sore eyes (11%) and nausea (11%). As feared, some eye reactions caused the most serious adverse effects, lasting weeks, months or even years after, discontinuation of SJW, rendering users unable to use bright light treatment or face daylight.
- 59% said they would use SJW again while 34% said they would not.
In summary, there is clinical evidence that St John's Wort is an effective treatment for mild to moderate depression. Although SAD is a form of depressive illness, it is only sub-syndromal SAD (the mild version of SAD) that falls into the category of mild to moderate depression. The symptoms and features of SAD differ from those of other forms of depression and sensitivity to light is one characteristic of severe SAD, which may render use of SJW impossible.
SJW in its existing OTC formulations interacts with many prescription medications including, it appears from the survey, antidepressant medication.
It is clear from SADA's survey that a large number of SJW sufferers preferred it to the clinically-proven treatments of bright light and antidepressant medication. Nevertheless, over a third of users experienced adverse effects, which ranged from mild to disabling in the long term and would not use SJW again.
Because there is little clinical evidence about SJW and its different formulations, which are not required by law to be published, nobody is currently able to reverse the negative effects or knows what the long term effects on the eye may be.
Consequently, the SAD association does not recommend the use of any SJW product for treatment of SAD and will not do so, until UK clinical trials have taken place and SJW has been licensed as a bona fide prescription medicine.