Background: Depression is the most common mental disorder, affecting about 3.8% of the population worldwide. Clinical symptoms of depression include sadness, anxiety and frequent mood swings, among others. Selective serotonin reuptake inhibitors (SSRIs), psychotherapy and behavioral therapy are commonly used for the treatment of this condition. Since SSRIs are associated with various side effects, extract of St. John's wort (SJW) has been suggested as an effective alternative. However, there are conflicting studies regarding its efficacy. Many studies have reported positive outcomes with low adverse effects, while others did not find it to be a suitable alternative.
Objectives: To analyze the available studies using SJW for depression therapy and to thoroughly evaluate its effectiveness compared to SSRIs and placebo.
Material and methods: Relevant articles for our meta-analysis were found using Medline (via PubMed), Cinahl (via EBSCO), Scopus, and Web of Sciences databases. Studies were included as per the predefined Population, Intervention, Comparison, Outcomes and Study (PICOS) criteria. A demographic summary of the patients treated with either SJW, placebo or SSRIs was collected and Hamilton Depression Rating Scale (HAMD) scores were extracted. Risks of bias analysis, diagnostic odds ratio (OR), risk ratio (RR), and sensitivity calculation were evaluated using Revman software, and the publication bias was assessed using MedCalc software.
Results: Fourteen clinical trials with a total of 2270 depression patients were included in accordance with the inclusion criteria. All analyzed papers were published between 2000 and 2022. For patients treated with either SSRIs or SJW, a pooled OR of 2.44 with a 95% confidence interval (95% CI) of 1.33-4.45 was obtained. The data were heterogeneous, with a tau2 value of 0.54, χ2 value of 31.05, degrees of freedom (df) value of 7, I2 value of 77%, and an overall Z-value of 2.90 with p = 0.004.
Conclusion: Our research supports the use of SJW as it reduced the number of depressive patients and their HAMD scores while having fewer risks and side effects than conventional medications.
Keywords: SSRIs; St. John’s wort; depression; mental disorder; randomized controlled trials.