A Government-funded study will compare the safety and effectiveness of St John's wort, a common herbal supplement, and citalopram, a standard antidepressant, in the treatment of minor depression.
The four-year study, being conducted at three sites, will see 300 participants with minor depression randomly assigned a standardised extract of St John's wort (Hypericum perforatum), citalopram, or placebo in a 12-week double-blind trial.
Researchers will assess changes in patients' symptoms, functioning and quality of life. Those who show no improvement will receive the active treatment they had not been assigned before, while patients with improved symptoms will take their assigned treatment for another 14 weeks for a total of 26 weeks.
The US National Institute of Mental Health (NIMH), the National Center for Complementary and Alternative Medicine (NCCAM), and the Office of Dietary Supplements (ODS) are providing around $4 million in funding for the research.
Minor depression is a common disorder that may impair a person's functioning and quality of life and is a serious risk factor for major depression, yet often underdiagnosed and undertreated. Many people take St John's wort without consulting their doctors. The study aims to determine how the herbal agent and the antidepressant fit in the overall management of the disorder.
"There is high public interest in herbal remedies for depression," said Dr Stephen E. Straus, director of NCCAM. "Our intent is to study St John's wort for the spectrum of depressive conditions for which the public considers its use. This new study extends our earlier research efforts from the more serious form of depression to a clinically less serious one, yet one that is, in fact, of considerable public health significance," he added.
The team will recruit men and women aged 18 to 85 who have experienced depressive symptoms for at least six months but less than two years continuously without meeting criteria for a major depressive episode or dysthymia within the past year. Other mental disorders, such as schizophrenia, bipolar disorder, anxiety and substance use disorders are also excluded.
Participants will be interviewed at an initial screening visit, during the initial two-week period when they are withdrawn from all medication, at baseline, and every two weeks thereafter during the study.