Does St. John’s wort work?

A meta-analysis of St. John’s wort trials was recently published in the British Journal of Medicine(1996).

Basically, the study concluded that St. John’s wort has superior efficacy to placebo and similar efficacy to antidepressants.

Drop-out rates due to side effects were 0.8% to 3.0%

And overall rates of side effects were greater with standard antidepressants. Sound good??

Well, let’s take a closer look at the study done. We find the following:

• There were only 4 studies done comparing St. John’s wort to regular antidepressants (tricyclics) as compared to 10 done comparing the drug to placebo.

• The average Hamilton depression score for the pts in the studies was about 20, which means that the pts were only mildly depressed. [The Hamilton depression scale is the major scale used in many clinical trials. The usual criteria in antidepressant trials are: severe depression >28; moderate depression 23-27; mild depression <22.]>

• Plus, only one of the studies in these four groups used actual DSM III-R Criteria. All of the rest used identified the pts using ICD-9 criteria for neurotic depression/adjustment disorders with depressed mood. So, this tells you again that most of these pts were only mildly depressed, and in most pts with adjustment disorders, the symptoms usually go away on their own even without any sort of treatment.

• Note that the average trial length was 5 weeks, which is pretty short given that most antidepressants take a couple of weeks to work.

• Plus, the average dose of antidepressant was considerably low (62.5 mg). The average therapeutic dose is 150-200 mg.

So, we are not convinced that St. John’s wort is doing much good for our patients and should probably wait for more literature to come out supporting its use before prescribing it to our patients.

Category: Pharmacology Notes