Association between women’s health–related Chinese herbal formula use and changes in PHQ-4 scores: A population-based cohort study from the Taiwan biobank

Objective Depression and anxiety are among the most prevalent mental health conditions worldwide and disproportionately affect women. This study aimed to examine whether the use of Chinese herbal medicine (CHM) for women’s health is associated with changes in Four-Item Patient Health Questionnaire (PHQ-4) scores among women in Taiwan. Material and Methods We analyzed data from 4,456 women in the Taiwan Biobank after excluding those with missing CHM or PHQ-4 data. Participants were categorized as CHM users (n = 411) or non-users (n = 4,045) and retrospectively followed over a median of four years. We examined whether different CHM indications—tocolysis, recuperation, menstrual regulation, and menopause management—were associated with PHQ-4 score changes using paired tests and multivariable regression models. Results At baseline, CHM users had higher PHQ-4 scores than non-users. Both groups showed significant score reductions (p < 0.001), with a greater annual decrease in the CHM group (β = -0.07, p = 0.016). Compared with non-users, the Regulate Menstruation group showed a trend toward greater annual PHQ decline (LS-mean difference = −0.095, p = 0.057). Among those with PHQ-4 ≥ 3, the tocolysis group showed the largest improvement (mean change =−1.4). Conclusion Use of women’s health–related CHM was associated with reductions in PHQ-4 scores among women. Formulas prescribed for menstrual regulation and tocolysis appeared to be particularly beneficial in improving psychological distress. These findings suggest that CHM may have a potential role as part of integrative strategies to support women’s mental health in population settings.