An extract manufactured from the herbal remedy St. John's Wort is just as effective in treating people with moderate to severe depression as a commonly prescribed anti-depressant, according to research published in the British Medical Journal.

In a six week study involving more than 300 people aged 18 to 70, the researchers found 50 percent of patients taking St. John's Wort reported their condition improved, compared with only 35 percent taking Paroxetine, brand name Paxil.

The team also found fewer side effects among those taking St. John's Wort, compared with patients taking Paxil.

The study authors said they support the use of St. John's Wort as an alternative to treat depression.