I have blogged about the herbal antidepressant before; for instance about the fact that it can cause potentially dangerous herb-drug interactions. When taken alone, however, it seems to be both safe and efficacious in reducing the symptoms of depression. This notion has just been confirmed yet again.
A new systematic review evaluated St. John’s wort (SJW) for the treatment of Major Depressive Disorder (MDD). The objectives of this review were to (1) evaluate the efficacy and safety of SJW in adults with MDD compared to placebo and active comparator and (2) evaluate whether the effects vary by severity of MDD.
The authors searched 9 electronic databases and existing reviews to November 2014. Two independent reviewers screened the citations, abstracted the data, and assessed the risk of bias. They included randomized controlled trials (RCTs) examining the effect of at least a 4-week administration of SJW on depression outcomes against placebo or active comparator in adults with MDD. Risk of bias was assessed using the Cochrane Risk of Bias tool and USPSTF criteria. Quality of evidence (QoE) was assessed using the GRADE approach.
Thirty-five studies examining 6993 patients met inclusion criteria; 8 studies evaluated a SJW extract that combined 0.3 % hypericin and 1-4 % hyperforin. SJW was associated with more treatment responders than placebo (relative risk [RR] 1.53; 95 % confidence interval [CI] 1.19, 1.97; I(2) 79 %; 18 RCTs; N = 2922, moderate QoE; standardized mean differences [SMD] 0.49; CI 0.23, 0.74; 16 RCTs; I(2) 89 %, N = 2888, moderate QoE). Compared to antidepressants, SJW participants were less likely to experience adverse events (OR 0.67; CI 0.56, 0.81; 11 RCTs; moderate QoE) with no difference in treatment effectiveness (RR 1.01; CI 0.90, 1.14; 17 RCTs, I(2) 52 %, moderate QoE; SMD -0.03; CI -0.21, 0.15; 14 RCTs; I(2) 74 %; N = 2248, moderate QoE) in mild and moderate depression.
The authors concluded that SJW monotherapy for mild and moderate depression is superior to placebo in improving depression symptoms and not significantly different from antidepressant medication. However, evidence of heterogeneity and a lack of research on severe depression reduce the quality of the evidence. Adverse events reported in RCTs were comparable to placebo and fewer compared with antidepressants. However, assessments were limited due to poor reporting of adverse events and studies were not designed to assess rare events. Consequently, the findings should be interpreted with caution.
This is an excellent review from a reputable and independent team. The findings are therefore trustworthy.
Does that mean that we can now recommend SJW for patients suffering from depression?
Perhaps – but we need to keep an eye on the interaction issue. As a sole treatment, SJW is much safer than conventional antidepressants. But if a patient takes other medicines, we ought to be very careful.
Other currently unresolved issues are the questions of which extract and which dose. At present, there is not enough evidence to provide conclusive answers to either of these, and therefore the enthusiasm of many doctors for prescribing SJW is understandably limited.
Irrespective of these problems, I have to say that SJW is without question one of the biggest ‘success stories’ from the realm of alternative medicine. Pity that there are not more of them!