2.1. Inclusion and exclusion criteria
Inclusion criteria were as follows: (1) Enrolled women with at least 12 months of menopause at baseline, and without the physical disease; (2) women experienced postmenopausal depression and did not undergo hormone therapy; (3) were treated with an oral phytoestrogen; (4) reported data that can be used to calculate the effectiveness; (5) the study was an RCT.
Studies were excluded due to the following reasons:(1) reported previous or current use of hormone therapy, (2) history of ovariectomy or hysterectomy, or no menopausal symptoms; (3) numerical outcome data was not provided, (4) abstract of meeting or letters. The degree of mental disorders was not considered among the inclusion or exclusion criteria.
2.2. Data sources and search strategy
A comprehensive search was conducted for relevant studies that were published in English or Chinese, in databases including PubMed, the Cochrane Library, Chinese Biomedical Literature Database, Web of Science, and EMBASE on November 25, 2020. The search keywords included (depression OR Depress* OR blue* OR melancho*) AND (”Plant Estrogens” OR ”Phyto-Estrogen” OR ”Estrogen-Like Plant Extracts”) AND (postmenopausal* OR menopause* OR ”postmenopausal period” OR involutional)]. Details on the search strategy have been provided in Supplemental Material Table 1. The reference lists of the studies were searched manually to identify additional studies23. The Clinical Trials.gov website was also searched for RCTs that were registered as completed but not yet published24. A flow diagram of the systematic search and study selection process is shown in Figure 1.