Byline: by Professor George Lewith

AM I worried about the latest 'finding' that the herb St John's wort -- commonly used to treat mild depression -- is useless? Far from it: I shall happily continue recommending it to patients.

There have been countless clinical trials on the herb's effectiveness and safety, and the jury has considered and reconsidered the evidence many, many times. So many times, in fact, that you would easily find six or so studies that concluded it was not effective.

Add to them the report earlier this month that clinicians at Global Neuroscience Initiative Foundation, a mental health charity, are unimpressed with St John's wort, preferring other herbals, such as passion flower, for depression, stress and anxiety.

Having worked in complementary medicine for many years , I know of so many more studies that have found St John's wort to be effective and well-tolerated.

The new report is just one study. I much prefer to draw my conclusions from systematic reviews, in which scientists bring together many well-designed studies (perhaps 50) and compare the entire body of evidence; this has much more meaning than a one-off study.

What shows up over and over again in these wide reviews is that this herb is as effective in treating mild to moderate depression as any of the pharmaceutical medications such as SSRIs (selective serotonin reuptake inhibitors), most famously Prozac.

Let me make it clear: I am not talking about using the herb in major depressions where the patient is suicidal or a danger to others, nor am I talking about day-to-day blues. 'Mild to moderate' depression can be debilitating and life-changing in a negative way. …