Trial Studies St. John’s Wort for Minor Depression

Researchers are now recruiting for a clinical trial that examines the use of St. John’s wort (SJW), a common herbal supplement, for the treatment of minor depression.

The researchers will randomly assign a total of 300 participants with minor depression to a standardized extract of SJW, citalopram (a standard antidepressant), or placebo in a 12-week double-blind trial. The researchers will assess changes in patients’ symptoms, functioning, and quality of life. Those patients 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 three-site study is being funded with more than $4 million from the National Institute of Mental Health, the National Center for Complementary and Alternative Medicine, and the Office of Dietary Supplements. The four-year study began in February 2003.

A number of other studies have examined SJW for major depression, says David Mischoulon, MD, PhD, staff psychiatrist at Massachusetts General Hospital in Boston. He is also the sub-investigator at the Boston site.

"Overall, the body of evidence is encouraging. The overall trend is that SJW is probably good for major depression that is in the mild-to-moderate range of severity and less effective for more severe depression," he says. "That was part of what led us to think about studying SJW for minor depression. We thought that if SJW treats milder illness most effectively, then this particular population might be likely to benefit."

Men and women ages 18-85 who meet diagnostic criteria for minor depression are eligible to participate. They must 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. Additional exclusionary criteria include other mental disorders, such as schizophrenia, bipolar disorder, anxiety, and substance use disorders. Individuals with some active physical illnesses, such as cardiovascular, renal, respiratory, endocrine, neurological, or blood diseases also are not eligible for the study.

Depression seems to attack women more frequently than men, at a ratio of about 1.5 to 1, Mischoulon says. He’s not sure why that is the case, but women may be more likely to seek help if they are feeling psychological distress. "These studies may need nothing more than a reflection of the willingness of certain people to seek help. It may be possible that depression may be equally common in men."

Many people who take SJW for minor depression probably do so without having had a formal diagnosis by a psychiatrist, especially since the milder symptoms of minor depression make it tricky to diagnose, he says.

The symptoms of minor depression are fewer in number and cause less impairment than those involving a major depressive disorder. These symptoms include either a depressed mood most of the day and nearly every day or a markedly diminished interest or pleasure in daily activities, plus two to four of the following symptoms: significant weight loss or gain, or decrease or increase in appetite; disturbance in sleep pattern; noticeable agitation or slowness; fatigue or loss of energy; inappropriate feelings of worthlessness or guilt; diminished ability to concentrate, indecisiveness; recurrent thoughts of death or suicide.

Recruiting for a study like this can be difficult because a lot of people with minor depression may be reticent to actually get into treatment, Mischoulon says. "Their symptoms aren’t severe, and they are functioning more or less normally. It is a challenging study to recruit because it is a disorder in which people are less likely to ask for help."

For more information about the study or recruitment, contact the following study sites:

  • Boston, MA, at Massachusetts General Hospital. Principal investigator: Andrew A. Nierenberg, MD; coordinator: Alana Burns at (617) 724-3222. 
  • Los Angeles, CA, at Cedars-Sinai Medical Center. Principal investigator: Mark Rapaport, MD; coordinator: Christina Kustak at (310) 423-0735.
  • Pittsburgh, PA, at the University of Pittsburgh. Principal investigator: Robert Howland, MD; coordinator: Michael Lightfoot at (412) 246-5735.