Abstract
INTRODUCTION: A boxed-warning in antidepressant labeling
now informs prescribers of the potential for treatmentemergent
suicidal to occur. Consequently, alternative
“natural” antidepressant therapies widely viewed to be devoid
of this risk, such as St. John’s wort (SJW) and s-adenosyl
methionine (SAM-e), may experience a resurgence in
popularity and expansion of use beyond mild forms of
depressive illness. The purpose of this article is to critically
assess whether the clinical evidence supports the use of SJW
and SAM-e as alternatives to conventional antidepressants in
the treatment of major depressive disorder (MDD). In addition,
this article evaluates whether the behavioral adverse event
profiles of SJW and SAM-e suggest an increased risk for
suicidal, like their conventional counterparts. METHODS: A
comprehensive literature review was performed (Jan
1975-July 2010) to identify all English language reports of
placebo-controlled studies of SJW and SAM-e conducted for
psychiatric indications. MDD studies were categorized as
“positive” or “negative” based on statistical superiority to
placebo on prospectively-defined, primary, clinician-rated
efficacy parameters (e.g., change in Hamilton Depression
scores [HAM-D] or Montgomery-Asberg Depression Rating
Scale [MADRS] total). Treatment effect size (Cohen’s d) was
also calculated in each case to assess the clinical relevance of
the findings. Behavioral-related adverse events were
summarized by treatment. RESULTS: Ten of 14 (71%) SJW
studies in mild-to-moderate MDD were positive. The mean
and median effect sizes for HAM-D change in those studies
were 0.64 and 0.48, respectively, indicative of a moderatelylarge
treatment effect. In the few studies that included
patients with severe symptoms, however, or which evaluated
long-term maintenance of effect, SJW did not differentiate
from placebo. The majority of SAM-e studies in MDD were also
positive (8/14, 57%); however, most were methodologically
flawed to some extent. Based on the magnitude of the
treatment-effect size in a number of positive studies, SJW
appears to be useful for the short-term treatment of
mild-to-moderate depressive illness in adults. Existing data do
not support the use of SJW in more severely depressed
individuals. The SAM-e clinical data also are strongly
suggestive of antidepressant efficacy; however, until more
rigorously generated data become available it is not possible
to reach a more definitive conclusion. There are no long-term
treatment data that convincingly demonstrate long-term
maintenance of effect for either product. The reviewed studies
did not reveal evidence of treatment-emergent suicidal,
suggesting that this risk for either product is low. However, the
studies examined were not prospectively designed to detect
such events and therefore were likely unable to reliably assess
this risk.
(Altern Med Rev 2011;16(1):17-39)